chore(deps): update go to 1.21

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
go (source)	golang	minor	1.20 -> 1.21

---

Release Notes

golang/go (go)

v1.21.0

v1.20.7

v1.20.6

v1.20.5

v1.20.4

v1.20.3

v1.20.2

v1.20.1

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.

[renovate]

⚠ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: go.sum

Command failed: docker run --rm --name=renovate_a_sidecar --label=renovate_a_child --memory=3584m -v "/tmp/worker/b6e215/485d33/repos/github/clevyr/mailhog":"/tmp/worker/b6e215/485d33/repos/github/clevyr/mailhog" -v "/tmp/worker/b6e215/485d33/cache":"/tmp/worker/b6e215/485d33/cache" -e GOPATH -e GOPROXY -e GOSUMDB -e GOFLAGS -e CGO_ENABLED -e GIT_CONFIG_KEY_0 -e GIT_CONFIG_VALUE_0 -e GIT_CONFIG_KEY_1 -e GIT_CONFIG_VALUE_1 -e GIT_CONFIG_KEY_2 -e GIT_CONFIG_VALUE_2 -e GIT_CONFIG_COUNT -e CONTAINERBASE_CACHE_DIR -w "/tmp/worker/b6e215/485d33/repos/github/clevyr/mailhog" ghcr.io/containerbase/sidecar:9.8.2 bash -l -c "install-tool golang 1.21.0 && go get -d -t ./... && go mod tidy && go mod tidy"
/usr/local/bin/docker: line 4: .: filename argument required
.: usage: . filename [arguments]
[16:36:48.198] INFO (38): Downloading file ...
    url: "https://dl.google.com/go/go1.21.linux-amd64.tar.gz"
    output: "/tmp/worker/b6e215/485d33/cache/containerbase/38a6f194ec41da4bde993a4d44636b9855533fe960b6936851bb324b70fde620/go1.21.linux-amd64.tar.gz"
[16:36:48.239] FATAL (38): Response code 404 (Not Found)
    err: {
      "type": "HTTPError",
      "message": "Response code 404 (Not Found)",
      "stack":
          HTTPError: Response code 404 (Not Found)
              at _Request._onResponseBase (/snapshot/dist/containerbase-cli.js:39606:25)
              at _Request._onResponse (/snapshot/dist/containerbase-cli.js:39661:18)
              at ClientRequest.<anonymous> (/snapshot/dist/containerbase-cli.js:39676:17)
              at Object.onceWrapper (node:events:652:26)
              at ClientRequest.emit (node:events:549:35)
              at ClientRequest.emit (node:domain:482:12)
              at HTTPParser.parserOnIncomingClient (node:_http_client:642:27)
              at HTTPParser.parserOnHeadersComplete (node:_http_common:117:17)
              at TLSSocket.socketOnData (node:_http_client:505:22)
              at TLSSocket.emit (node:events:537:28)
      "code": "ERR_NON_2XX_3XX_RESPONSE",
      "timings": {
        "start": 1691512608208,
        "socket": 1691512608209,
        "lookup": 1691512608210,
        "connect": 1691512608213,
        "secureConnect": 1691512608218,
        "upload": 1691512608218,
        "response": 1691512608234,
        "end": 1691512608236,
        "phases": {
          "wait": 1,
          "dns": 1,
          "tcp": 3,
          "tls": 5,
          "request": 0,
          "firstByte": 16,
          "download": 2,
          "total": 28
        }
      },
      "name": "HTTPError",
      "options": {
        "agent": {},
        "decompress": true,
        "timeout": {},
        "prefixUrl": "",
        "ignoreInvalidCookies": false,
        "context": {},
        "hooks": {
          "init": [],
          "beforeRequest": [],
          "beforeError": [],
          "beforeRedirect": [],
          "beforeRetry": [],
          "afterResponse": []
        },
        "followRedirect": true,
        "maxRedirects": 10,
        "throwHttpErrors": true,
        "username": "",
        "password": "",
        "http2": false,
        "allowGetBody": false,
        "headers": {
          "user-agent": "got (https://github.com/sindresorhus/got)",
          "accept-encoding": "gzip, deflate, br"
        },
        "methodRewriting": false,
        "retry": {
          "limit": 2,
          "methods": [
            "GET",
            "PUT",
            "HEAD",
            "DELETE",
            "OPTIONS",
            "TRACE"
          ],
          "statusCodes": [
            408,
            413,
            429,
            500,
            502,
            503,
            504,
            521,
            522,
            524
          ],
          "errorCodes": [
            "ETIMEDOUT",
            "ECONNRESET",
            "EADDRINUSE",
            "ECONNREFUSED",
            "EPIPE",
            "ENOTFOUND",
            "ENETUNREACH",
            "EAI_AGAIN"
          ],
          "backoffLimit": null,
          "noise": 100
        },
        "method": "GET",
        "cacheOptions": {},
        "https": {},
        "resolveBodyOnly": false,
        "isStream": true,
        "responseType": "text",
        "url": "https://dl.google.com/go/go1.21.linux-amd64.tar.gz",
        "pagination": {
          "countLimit": null,
          "backoff": 0,
          "requestLimit": 10000,
          "stackAllItems": false
        },
        "setHost": true,
        "enableUnixSockets": false
      }
    }
[16:36:48.240] INFO (38): Download completed with errors  in 42ms.
Download failed: https://dl.google.com/go/go1.21.linux-amd64.tar.gz