Execute PR-triggered cpp-upload only if there's no release label (#4806)

### What

* (most likely) fixes  #4805

It seems what happened on 0.12 is that we first executed the regular
release build which uploaded the correct C++ artifact
https://github.com/rerun-io/rerun/actions/runs/7464893722/job/20313070683
and THEN ran the regular PR ci which only uploads a linux artifact,
overwriting the previous
https://github.com/rerun-io/rerun/actions/runs/7464905304/job/20313103967


### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/4806/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/4806/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/4806/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG

- [PR Build Summary](https://build.rerun.io/pr/4806)
- [Docs
preview](https://rerun.io/preview/62c0913144e49334376cf643a71db16bac22d13d/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/62c0913144e49334376cf643a71db16bac22d13d/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

.github/workflows/on_pull_request.yml

@@ -81,7 +81,7 @@ jobs:
 
   build-rerun_c-and-upload:
     name: "Build & Upload rerun_c (Linux x64)"
-    if: github.event.pull_request.head.repo.owner.login == 'rerun-io'
+    if: github.event.pull_request.head.repo.owner.login == 'rerun-io' && !contains(github.event.pull_request.labels.*.name, 'release')
     uses: ./.github/workflows/reusable_build_and_upload_rerun_c.yml
     with:
       CONCURRENCY: pr-${{ github.event.pull_request.number }}
@@ -90,7 +90,7 @@ jobs:
 
   build-rerun-cli-and-upload:
     name: "Build & Upload rerun-cli (Linux x64)"
-    if: github.event.pull_request.head.repo.owner.login == 'rerun-io'
+    if: github.event.pull_request.head.repo.owner.login == 'rerun-io' && !contains(github.event.pull_request.labels.*.name, 'release')
     uses: ./.github/workflows/reusable_build_and_upload_rerun_cli.yml
     with:
       CONCURRENCY: pr-${{ github.event.pull_request.number }}
@@ -99,6 +99,7 @@ jobs:
 
   bundle-and-upload-rerun_cpp:
     name: "Bundle and upload rerun_cpp_sdk.zip"
+    if: github.event.pull_request.head.repo.owner.login == 'rerun-io' && !contains(github.event.pull_request.labels.*.name, 'release')
     needs: [build-rerun_c-and-upload]
     uses: ./.github/workflows/reusable_bundle_and_upload_rerun_cpp.yml
     with:

.github/workflows/reusable_publish_rerun_c.yml

@@ -1,4 +1,4 @@
-name: Build and publish wheels
+name: Build and publish C++ SDK
 
 on:
   workflow_call: