Remove CI check for sign off (#16776)

Since we don't require one anymore.

.github/PULL_REQUEST_TEMPLATE.md

@@ -9,6 +9,5 @@
   - End with either a period (.) or an exclamation mark (!).
   - Start with a capital letter.
   - Feel free to credit yourself, by adding a sentence "Contributed by @github_username." or "Contributed by [Your Name]." to the end of the entry.
-* [ ] Pull request includes a [sign off](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#sign-off)
 * [ ] [Code style](https://element-hq.github.io/synapse/latest/code_style.html) is correct
   (run the [linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

.github/workflows/tests.yml

@@ -12,10 +12,6 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  check-signoff:
-    if: "github.event_name == 'pull_request'"
-    uses: "matrix-org/backend-meta/.github/workflows/sign-off.yml@v2"
-
   # Job to detect what has changed so we don't run e.g. Rust checks on PRs that
   # don't modify Rust code.
   changes:
@@ -706,15 +702,14 @@ jobs:
           needs: ${{ toJSON(needs) }}
 
           # Various bits are skipped if there was no applicable changes.
-          # The newsfile and signoff lint may be skipped on non PR builds.
+          # The newsfile lint may be skipped on non PR builds.
           skippable: |
             trial
             trial-olddeps
             sytest
             portdb
             export-data
             complement
-            check-signoff
             lint-newsfile
             cargo-test
             cargo-bench

changelog.d/16776.misc

@@ -0,0 +1 @@
+Remove CI check for sign off as we require an CLA signature instead.