Align branch names across platforms

### What is this about?

The platform teams are aligning on most processes and branch names is one outstanding change that needs to be done. For extension the following changes need to be made:

- `master` re-named to `stable`
- This requires a number of GH Actions to be updated
- `Version-vx.x.x` re-named `release/x.x.x
- This requires GH Actions and Runway Configurations to be updated

### Scenario

_No response_

### Design

_No response_

### Technical Details

_No response_

### Threat Modeling Framework

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### Acceptance Criteria

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### Stakeholder review needed before the work gets merged

- [ ] Engineering (needed in most cases)
- [ ] Design
- [ ] Product
- [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
- [ ] Security
- [ ] Legal
- [ ] Marketing
- [ ] Management (please specify)
- [ ] Other (please specify)

### References

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Search the repository's GitHub Actions and Runway configurations for the current master and Version-vx.x.x branch names. Trace every matching reference across the extension's automation configuration, then verify that all branch references use stable and release/x.x.x consistently.

Written by the indexing model from the issue text.