…tiate between a namespace that's temporary unavailable and not active.\r\nThis new failure will be returned with a gRPC unavailable error and should be retried by clients automatically.

**What changed?**
Collapse two actions into one to avoid problems with multi-line strings
and GITHUB_OUTPUT

**Why?**
Fix breakage

<!-- Describe what has changed in this PR -->
Add batch update execution options operation type enum

<!-- Tell your future self why have you made these changes -->
For use in `DescribeBatchOperation`

<!-- Are there any breaking changes on binary or code level? -->
**Breaking changes**

<!-- If this breaks the Server, please provide the Server PR to merge
right after this PR was merged. -->
**Server PR**

**What changed?**

Add a warning to the GitHub PR template reminding everyone that both
Server AND SDK teams must sign off on a PR before it's merged.

**Why?**

'Cause people have merged things a couple times now without SDK review.

**Breaking changes**

None