ci: Report changelog format problems rather than failing on them

.github/workflows/ModuleCI.yml

@@ -12,15 +12,20 @@ jobs:
     runs-on: [ubuntu-latest]
     steps:
       - uses: actions/checkout@v4
-      # Validates CHANGELOG.md against the Keep a Changelog format. Skipped when the
+      # Validates CHANGELOG.md against the Keep a Changelog format. Reports rather than
+      # fails: the action also enforces a SemVer rule that a patch release may contain
+      # only Fixed and Security sections, and existing psake module histories violate
+      # that in releases already published, which no edit can undo. Raise to error once
+      # a repository is clean, per repository, rather than org-wide.
+      # Skipped when the
       # repository has no changelog, so a consumer without one is not failed for it.
       # validation_depth defaults to 10 entries; raised so older releases are checked
       # too, which is where format drift accumulates unnoticed.
       - name: Validate changelog (keepachangelog)
         if: hashFiles('CHANGELOG.md') != ''
         uses: mindsers/changelog-reader-action@v2
         with:
-          validation_level: error
+          validation_level: warn
           validation_depth: 100
           path: ./CHANGELOG.md
       - uses: streetsidesoftware/cspell-action@v6