feat: Run the full E2E suite set automatically on release PRs

.github/release-pr-body.md

@@ -0,0 +1,14 @@
+<!--
+Used verbatim as the body of release PRs created by giantswarm/github-workflows
+(see .github/workflows/zz_generated.create_release_pr.yaml).
+
+The `/run` line makes Tekton start the E2E tests as soon as the release PR is
+opened. cluster-test-suites expands to every suite for this provider when it
+detects a release PR, so the full set runs before the release is tagged.
+
+See https://github.com/giantswarm/roadmap/issues/4334
+-->
+
+The full set of E2E test suites for this provider runs automatically on this release PR.
+
+/run cluster-test-suites

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- CI: Run the full set of E2E test suites automatically on release PRs, via `.github/release-pr-body.md`. Towards https://github.com/giantswarm/roadmap/issues/4334
+
 ## [3.0.0] - 2026-08-05
 
 ### Changed