reusable_go_lint_test: Support private repo authentication

[maiquanghiep]

This PR adds go-private-repos-authentication input togo_lint_test and docker_pipeline workflow to allow Golang repos to use private modules.
If the input is enabled, it will change the git config to use PAT when downloading packages.
One important thing to note here: while it's recommended to set GOPRIVATE to control which modules the go command considers to be private and should therefore not use the proxy or checksum database (ref), I decided not to add the variable to support it so that the workflow's caller is cleaner. One example of that variable can be

      go-private-repos:
          description: 'Comma-separated list of private Go repositories'
          type: string
          default: 'github.com/babylonlabs-io/babylon-privat'

which can be used as below in the go_lint_test

      - name: Configure Private Module Access
        if: ${{ inputs.go-private-repos != '' }}
        run: |
          go env -w GOPRIVATE=${{ inputs.go-private-repos }} # inputs.go-private-repos is used here
          git config --global url."https://${{ secrets.GO_PRIVATE_TOKEN }}@github.com/".insteadOf "https://github.com/"

To make the above consideration work, the GOPROXY='https://proxy.golang.org,direct/ env must be set, which is true as it's the default value (e.g You can check the Print Go environment step of this workflow run).

Also https://docs.docker.com/build/ci/github-actions/secrets was referred to mount secrets to docker which is useful when reviewing docker_pipeline.
Example of workflow caller PR babylonlabs-io/finality-provider#43

[filippos47]

Tidy PR as usual, thanks Hiep!