ci: Run Build job on Bitrise tahoe runners

The Build job on GitHub-hosted ubuntu-latest repeatedly died mid-way through
make preMerge with "The runner has received a shutdown signal" (five jobs
between Sep 30 and Oct 1), which is the hosted runner being killed for
resource exhaustion. Move the job to the Bitrise tahoe pool using the same
runs-on label pattern as sentry-cocoa, and add the actionlint label config
cocoa uses so the custom label lints cleanly.

Keep the job name unchanged because it is a required status check in the
main branch ruleset.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: itaybre

.github/actionlint.yaml

@@ -0,0 +1,4 @@
+# Custom runner labels for actionlint (same approach as sentry-cocoa).
+self-hosted-runner:
+  labels:
+    - bitrise_pool_name:tahoe

.github/workflows/build.yml

@@ -11,8 +11,11 @@ concurrency:
 
 jobs:
   build:
+    # Job name is a required status check in the main branch ruleset; keep it stable.
     name: Build Job ubuntu-latest - Java 17
-    runs-on: ubuntu-latest
+    # Runs on Bitrise-hosted runners (same pattern as sentry-cocoa) instead of
+    # GitHub-hosted ubuntu-latest, which ran out of memory during `make preMerge`.
+    runs-on: ["bitrise_pool_name:tahoe"]
 
     env:
       GRADLE_ENCRYPTION_KEY: ${{ secrets.GRADLE_ENCRYPTION_KEY }}