Update rulesets-metadata-restrictions-notes.md (#59425)

Co-authored-by: mc <42146119+mchammer01@users.noreply.github.com>

Author: patrick-knight

data/reusables/repositories/rulesets-metadata-restrictions-notes.md

@@ -1 +1,4 @@
-> [!NOTE] If you squash merge a branch, all commits on that branch must meet any metadata requirements for the base branch.
+> [!NOTE]
+> If you squash merge a branch, all commits on that branch must meet any metadata requirements for the base branch.
+> 
+> When using end-of-line anchors in regular expressions, use `\n?$` rather than `$` alone. The optional `\n?` matches a trailing newline that may be present in Git push/CLI flows, while still working for commits created via the web UI and API.