Upgrade gulp version from 3 to 4

[sakamossan]

When running the build with Node 12 and later, an error occurs with graceful-fs v3, which gulp depends on. The error is as follows:

$ npx node --version
v14.21.3
$ npx gulp
fs.js:40
} = primordials;
    ^

ReferenceError: primordials is not defined
    at fs.js:40:5
    at req_ (/Users/sakamossan/.ghq/github.com/alexei/sprintf.js/node_modules/natives/index.js:143:24)
    at Object.req [as require] (/Users/sakamossan/.ghq/github.com/alexei/sprintf.js/node_modules/natives/index.js:55:10)
    at Object.<anonymous> (/Users/sakamossan/.ghq/github.com/alexei/sprintf.js/node_modules/vinyl-fs/node_modules/graceful-fs/fs.js:1:37)
    at Module._compile (internal/modules/cjs/loader.js:1114:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1143:10)
    at Module.load (internal/modules/cjs/loader.js:979:32)
    at Function.Module._load (internal/modules/cjs/loader.js:819:12)
    at Module.require (internal/modules/cjs/loader.js:1003:19)
    at require (internal/modules/cjs/helpers.js:107:18)

Since gulp v3 is out of support, it is a good time to upgrade.

If this PR is merged, it will be friendly to developers using apple silicon as they will not have to install node v10 to develop. (I confirmed that v4 gulp tasks runs on node v20)

ref

• gulp jobs test, dist & default fail on node v13 #191
• Gulp 3 is broken on Node 12 gulpjs/gulp#2324

Changes

• Upgraded gulp version to 4 to avoid this error
• gulpfile.js was also updated to match the gulp v4 API

Verification

After upgrading the gulp version, the build output remains the same.

before

$ cd ~/.ghq/github.com/alexei/sprintf.js
$ md5 dist/*.js | sort
MD5 (dist/angular-sprintf.min.js) = fd0f92f0c18e8c9eae965ca1076140ae
MD5 (dist/sprintf.min.js) = e4f895a680f0f7a9459651fc9b7a26f0

after

$ npx node --version
v20.4.0
$ npx gulp
[14:50:34] Using gulpfile ~/.ghq/github.com/sakamossan/sprintf.js/gulpfile.js
[14:50:34] Starting 'default'...
[14:50:34] Starting 'dist'...
[14:50:34] Starting 'test'...
[14:50:34] Starting 'lint'...
[14:50:34] Finished 'lint' after 11 ms
[14:50:34] Starting '<anonymous>'...
[14:50:34] Finished '<anonymous>' after 1.75 ms
[14:50:34] Finished 'test' after 13 ms
[14:50:34] Starting '<anonymous>'...
[14:50:34] Finished '<anonymous>' after 1.16 ms
[14:50:34] Finished 'dist' after 15 ms
[14:50:34] Finished 'default' after 16 ms
 28  -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_,------,
 0   -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_|   /\_/\
 0   -_-_-_-_-_-_-_-_-_-_-_-_-_-_-^|__( ^ .^)
     -_-_-_-_-_-_-_-_-_-_-_-_-_-_-  ""  ""

  28 passing (7ms)

$ md5 dist/*.js | sort
MD5 (dist/angular-sprintf.min.js) = fd0f92f0c18e8c9eae965ca1076140ae
MD5 (dist/sprintf.min.js) = e4f895a680f0f7a9459651fc9b7a26f0