ci: add core Apache Cloudberry (incubating) build and test workflow (a…

…pache#714)

Introduces foundational GitHub Actions workflow for Apache
Cloudberry (incubating) CI:

- Multi-stage build pipeline with skip detection
- Rocky Linux 9 containerized build environment
- RPM packaging and source tarball generation
- Installation verification
- Test matrix for core regression tests
  (subset starting point)
- Detailed test result parsing and reporting
- Comprehensive artifact management

The workflow provides:
- Clean build environment for each run
- Consistent test execution framework
- Automated installation testing
- Test result aggregation
- Clear job dependencies and progression
- Flexible CI skip mechanisms

Due to inconsistent test runs, disable the following from
greenplum_schedule:
- cbdb_parallel
- instr_in_shmem_verify

This commit establishes the initial CI pipeline for Apache Cloudberry
(incubating) with future test matrix expansion planned.

.github/pull_request_template.md

@@ -1,38 +1,49 @@
-<!--Thank you for contributing!-->
-<!--In case of an existing issue or discussions, please reference it-->
-fix #ISSUE_Number
-<!--Remove this section if no corresponding issue.-->
+<!-- Thank you for your contribution to Apache Cloudberry (incubating)! -->
 
----
-
-### Change logs
+Fixes #ISSUE_Number
 
-_Describe your change clearly, including what problem is being solved or what feature is being added._
+### What does this PR do?
+<!-- Brief overview of the changes, including any major features or fixes -->
 
-_If it has some breaking backward or forward compatibility, please clary._
+### Type of Change
+- [ ] Bug fix (non-breaking change)
+- [ ] New feature (non-breaking change)
+- [ ] Breaking change (fix or feature with breaking changes)
+- [ ] Documentation update
 
-### Why are the changes needed?
+### Breaking Changes
+<!-- Remove if not applicable. If yes, explain impact and migration path -->
 
-_Describe why the changes are necessary._
+### Test Plan
+<!-- How did you test these changes? -->
+- [ ] Unit tests added/updated
+- [ ] Integration tests added/updated
+- [ ] Passed `make installcheck`
+- [ ] Passed `make -C src/test installcheck-cbdb-parallel`
 
-### Does this PR introduce any user-facing change?
+### Impact
+<!-- Remove sections that don't apply -->
+**Performance:**
+<!-- Any performance implications? -->
 
-_If yes, please clarify the previous behavior and the change this PR proposes._
+**User-facing changes:**
+<!-- Any changes visible to users? -->
 
-### How was this patch tested?
+**Dependencies:**
+<!-- New dependencies or version changes? -->
 
-_Please detail how the changes were tested, including manual tests and any relevant unit or integration tests._
+### Checklist
+- [ ] Followed [contribution guide](https://cloudberry.apache.org/contribute/code)
+- [ ] Added/updated documentation
+- [ ] Reviewed code for security implications
+- [ ] Requested review from [cloudberry committers](https://github.com/orgs/apache/teams/cloudberry-committers)
 
-### Contributor's Checklist
+### Additional Context
+<!-- Any other information that would help reviewers? Remove if none -->
 
-Here are some reminders and checklists before/when submitting your pull request, please check them:
+⚠️ **To skip CI:** Add `[skip ci]` to your PR title. Only use when necessary! ⚠️
 
-- [ ] Make sure your Pull Request has a clear title and commit message. You can take [git-commit](https://github.com/cloudberrydb/cloudberrydb/blob/main/.gitmessage) template as a reference.
-- [ ] Sign the Contributor License Agreement as prompted for your first-time contribution(*One-time setup*).
-- [ ] Learn the [coding contribution guide](https://cloudberrydb.org/contribute/code), including our code conventions, workflow and more.
-- [ ] List your communication in the [GitHub Issues](https://github.com/cloudberrydb/cloudberrydb/issues) or [Discussions](https://github.com/orgs/cloudberrydb/discussions) (if has or needed).
-- [ ] Document changes.
-- [ ] Add tests for the change
-- [ ] Pass `make installcheck`
-- [ ] Pass `make -C src/test installcheck-cbdb-parallel`
-- [ ] Feel free to request `cloudberrydb/dev` team for review and approval when your PR is ready🥳
+---
+<!-- Join our community:
+- Mailing list: [[email protected]](https://lists.apache.org/[email protected]) (subscribe: [email protected])
+- Discussions: https://github.com/apache/cloudberry/discussions -->