Improve local GoReleaser build process and development docs

[hslatman]

The goreleaser target has been adapted to allow for building CLI
releases that are very similar to the ones that we release as part of
our GitHub Actions release process. The target skips the hooks that
trigger binaries to be pushed to GCP, allowing the release process to
happen locally.

This PR also allows the GoReleaser process to be performed with
either its Pro or OSS version using a single config file.

Other changes in this PR:

• Updated documentation for contributing to the step codebase
• Replaced list of enabled linters with the current golangci-lint config
• Enabled git data to be embedded into binary
• Fixed some GoReleaser config deprecations
• Fixed the GoReleaser Pro download URL for AMD64
• Fixed some test cases that failed when ran using make test

Example build using Pro:

make goreleaser
  • by using this software you agree with its EULA, available at https://goreleaser.com/eula
  • running goreleaser v2.8.2
  • skipping after, post-hooks, and validate...
  • cleaning distribution directory
  • loading environment variables
  • getting and validating git state
    • git state                                      commit=ece761143dd381180c19ce41096e5f300c432601 branch=herman/goreleaser-improvements current_tag=v0.28.6 previous_tag=v0.28.5 dirty=false
    • pipe skipped or partially skipped              reason=validation is disabled
  • parsing tag
  • setting defaults
  • partial
    • adjusting environment                          by=target target=darwin_arm64 dist=dist/darwin_arm64
  • snapshotting
    • building snapshot...                           version=v0.28.6-next
  • running before hooks
    • running hook                                   hook=go mod download
  • ensuring distribution directory
  • setting up metadata
  • writing release metadata
  • loading go mod information
  • build prerequisites
  • building binaries
    • partial build                                  filter=target=darwin_arm64_v8.0 matches=darwin_arm64_v8.0
    • building                                       binary=dist/darwin_arm64/default_darwin_arm64_v8.0/bin/step
  • setting up metadata
  • storing artifacts metadata
  • copying binary to "bin/step"
  • build succeeded after 3s
  • thanks for using GoReleaser Pro!

Example build using OSS:

make goreleaser
  • your configuration specifies  pro: true
    explanation=
    │ Your configuration is for GoReleaser Pro.
    │ You are currently using GoReleaser OSS, so all the Pro-only features will be ignored.
    │ Use GoReleaser Pro to enable all the features.
  • skipping post-hooks and validate...
  • cleaning distribution directory
  • loading environment variables
  • getting and validating git state
    • git state                                      commit=ece761143dd381180c19ce41096e5f300c432601 branch=herman/goreleaser-improvements current_tag=v0.28.6 previous_tag=v0.28.5 dirty=false
    • pipe skipped or partially skipped              reason=disabled during snapshot mode
  • parsing tag
  • setting defaults
  • partial
  • snapshotting
    • building snapshot...                           version=v0.28.6-next
  • running before hooks
    • running                                        hook=go mod download
  • ensuring distribution directory
  • setting up metadata
  • writing release metadata
  • loading go mod information
  • build prerequisites
  • building binaries
    • partial build                                  match=target=darwin_arm64_v8.0
    • building                                       binary=dist/default_darwin_arm64_v8.0/bin/step
  • writing artifacts metadata
  • copying binary to "bin/step"
  • build succeeded after 3s
  • thanks for using GoReleaser!

[tashian]

Looks good to me! I tested this locally with goreleaser pro 2.8.2 and make.