ci: skip semantic PR title check for Dependabot PRs

Dependabot auto-generates titles with 'Bump' (uppercase), which
violates the lowercase-subject rule. Since Dependabot titles are
auto-generated and not human-controlled, skip the check for bot PRs.

Also add commit-message prefix to dependabot.yml so future PRs use
the 'chore(deps)' conventional commits prefix.

Signed-off-by: Sebastien Tardif <sebtardif@ncf.ca>

Author: SebTardif

.github/dependabot.yml

@@ -7,6 +7,8 @@ updates:
     labels:
       - dependencies
     open-pull-requests-limit: 5
+    commit-message:
+      prefix: "chore(deps)"
 
   - package-ecosystem: github-actions
     directory: /
@@ -15,11 +17,15 @@ updates:
     labels:
       - dependencies
     open-pull-requests-limit: 5
+    commit-message:
+      prefix: "chore(deps)"
 
   - package-ecosystem: docker
     directory: /
     schedule:
       interval: weekly
     labels:
       - dependencies
-    open-pull-requests-limit: 3
+    open-pull-requests-limit: 3
+    commit-message:
+      prefix: "chore(deps)"

.github/workflows/pr-title.yaml

@@ -10,6 +10,7 @@ permissions:
 jobs:
   semantic-title:
     name: Semantic PR Title
+    if: github.actor != 'dependabot[bot]'
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps: