chore: finish migration to bzlmod

- bump bazel to 6.4.0
- bump rules_go, gazelle, platforms
- enable bzlmod
- clear WORKSPACE (cannot remove yet due to examples)
- remove `gofmt`, #136
- remove Go MacOS x86_64 tests, #10

.bazelrc

@@ -1,3 +1,5 @@
+common --enable_bzlmod
+
 test --sandbox_default_allow_network=false
 test --test_output=errors
 
@@ -7,4 +9,4 @@ build --worker_sandboxing
 build --experimental_reuse_sandbox_directories
 build --incompatible_enable_cc_toolchain_resolution
 build --action_env BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
-build --experimental_output_directory_naming_scheme=diff_against_baseline
+build --experimental_output_directory_naming_scheme=diff_against_dynamic_baseline

.bazelversion

@@ -1 +1 @@
-6.3.0
+6.4.0

MODULE.bazel

@@ -3,9 +3,9 @@ module(
     version = "2.1.3",
 )
 
-bazel_dep(name = "platforms", version = "0.0.6")
+bazel_dep(name = "platforms", version = "0.0.8")
 
-bazel_dep(name = "rules_go", version = "0.41.0", dev_dependency = True)
+bazel_dep(name = "rules_go", version = "0.43.0", dev_dependency = True)
 
 go_sdk = use_extension(
     "@rules_go//go:extensions.bzl",
@@ -14,7 +14,7 @@ go_sdk = use_extension(
 )
 use_repo(go_sdk, "go_default_sdk")
 
-bazel_dep(name = "gazelle", version = "0.32.0", dev_dependency = True)
+bazel_dep(name = "gazelle", version = "0.34.0", dev_dependency = True)
 
 go_deps = use_extension(
     "@gazelle//:extensions.bzl",
@@ -24,5 +24,28 @@ go_deps = use_extension(
 go_deps.from_file(go_mod = "//:go.mod")
 use_repo(
     go_deps,
+    "com_github_stretchr_testify",
     "com_github_bazelbuild_buildtools",
 )
+
+toolchains = use_extension("//toolchain:ext.bzl", "toolchains")
+use_repo(toolchains, "zig_sdk")
+
+register_toolchains(
+    # if no `--platform` is specified, these toolchains will be used for
+    # (linux,darwin,windows)x(amd64,arm64)
+    "@zig_sdk//toolchain:linux_amd64_gnu.2.28",
+    "@zig_sdk//toolchain:linux_arm64_gnu.2.28",
+    "@zig_sdk//toolchain:darwin_amd64",
+    "@zig_sdk//toolchain:darwin_arm64",
+    "@zig_sdk//toolchain:windows_amd64",
+    "@zig_sdk//toolchain:windows_arm64",
+
+    # amd64 toolchains for libc-aware platforms:
+    "@zig_sdk//libc_aware/toolchain:linux_amd64_gnu.2.28",
+    "@zig_sdk//libc_aware/toolchain:linux_amd64_gnu.2.31",
+    "@zig_sdk//libc_aware/toolchain:linux_amd64_musl",
+    # arm64 toolchains for libc-aware platforms:
+    "@zig_sdk//libc_aware/toolchain:linux_arm64_gnu.2.28",
+    "@zig_sdk//libc_aware/toolchain:linux_arm64_musl",
+)