ci: allow merging chart changes without a version bump

.github/ct.yaml

@@ -4,5 +4,10 @@ chart-dirs:
   - charts
 # The chart intentionally ships without a maintainers field; don't fail on it.
 validate-maintainers: false
+# A pull request may change the chart without bumping its version. Such a change
+# simply is not released: chart-releaser skips a version that already has a
+# release, and the next version bump ships the accumulated changes. Requiring a
+# bump per pull request would force a chart release for every merge.
+check-version-increment: false
 # yamllint config matching the chart's inline-comment style.
 lint-conf: .github/lintconf.yaml

.github/workflows/ci.yaml

@@ -106,7 +106,14 @@ jobs:
         with:
           version: v3.16.3
 
+      # A merge that changes the chart without bumping its version must not fail
+      # here. chart-releaser detects the chart as changed since the last tag and
+      # repackages it, so without `skip_existing` the upload of an already
+      # released version aborts the job. Skipping leaves the existing release
+      # untouched; the changes ship with the next version bump.
       - name: Run chart-releaser
         uses: helm/chart-releaser-action@v1.7.0
+        with:
+          skip_existing: true
         env:
           CR_TOKEN: "${{ secrets.GITHUB_TOKEN }}"