fix: remove broken greet-new-contributors workflow (#77)

The actions/first-interaction greeting still referenced the upstream
invisible-squiggles template and posted off-brand bot comments on new
issues and PRs.

Author: michen00

.github/workflows/greet-new-contributors.yml

@@ -11,7 +11,6 @@ rules:
     min-spaces-from-content: 1
   line-length:
     ignore: |
-      .github/workflows/greet-new-contributors.yml
       .github/workflows/pre-commit-autoupdate.yml
     max: 100
     allow-non-breakable-words: true