feat: update existing PR summary comment instead of creating new ones

[joshjohanning]

When ENABLE_GITHUB_PULL_REQUEST_SUMMARY_COMMENT is enabled (it is by default?), super-linter now searches for an existing summary comment (identified by an HTML marker) and updates it in place, rather than creating a new comment on every push. This reduces comment noise / spamminess on pull requests with multiple subsequent pushes.

The implementation:
identify super-linter summary comments

• Lists existing PR comments and finds any with the marker
• Updates the existing comment via PATCH if found, or creates a new one
• Refactors CallGitHubApi to accept an optional HTTP method parameter (backwards-compatible, defaults to POST)

Closes: #7458

I verified that this new logic works in

• test: trigger super-linter PR summary comment joshjohanning-org/super-linter-test#1 (comment)

Readiness checklist

In order to have this pull request merged, complete the following tasks.

Pull request author tasks

• I checked that all workflows return a success.
• I included all the needed documentation for this change.
• I provided the necessary tests.
• I squashed all the commits into a single commit.
• I followed the
  Conventional Commit v1.0.0 spec.
• I wrote the necessary upgrade instructions in the
  upgrade guide.
• If this pull request is about and existing issue, I added the
  Fix #ISSUE_NUMBER or Close #ISSUE_NUMBER text to the description of
  the pull request.

Super-linter maintainer tasks

• Label as breaking if this change breaks compatibility with the previous
  released version.
• Label as either: automation, bug, documentation, enhancement,
  infrastructure.
• Add the pull request to a milestone, eventually creating one, that matches
  with the version that release-please proposes in the
  preview-release-notes CI job.