ci: Fix concurrency settings to allow parallel workflows on develop branch (#2391)

Updates the GitHub Actions workflow concurrency configuration to allow
parallel execution of workflows on the `develop` branch while
maintaining cancellation behavior for other branches.

## Problem
Previously, all workflow runs were subject to cancellation when new
commits were pushed to the same branch (`cancel-in-progress: true`).
This caused issues on the `develop` branch where important CI runs could
be prematurely cancelled, potentially missing critical feedback on the
main development branch.

## Solution
Modified the `concurrency` settings in `.github/workflows/build.yml` to
use separate concurrency groups and conditional cancellation:

```yaml
concurrency:
  # Use separate concurrency groups for develop vs other branches to prevent cross-cancellation
  group: ${{ github.workflow }}-${{ github.ref }}-${{ github.ref == 'refs/heads/develop' && github.run_number || 'branch' }}
  cancel-in-progress: ${{ github.ref != 'refs/heads/develop' }}
```

## Behavior
- **`develop` branch**: Each run gets its own concurrency group (using
`run_number`), allowing parallel execution without cancellation or
queuing delays
- **All other branches**: Shared concurrency group with
`cancel-in-progress: true` - workflows are cancelled when new commits
are pushed

This ensures that the `develop` branch can run multiple workflows in
parallel without interference while still providing the efficiency
benefits of workflow cancellation on feature branches and pull requests.

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.github/workflows/build.yml

@@ -28,8 +28,9 @@ on:
   workflow_dispatch:
 
 concurrency:
-  # Only cancel in-progress jobs or runs for the current workflow - matches against branch & tags
+  # Develop branch: Each run gets unique group (using run_number) for parallel execution
-  group: ${{ github.workflow }}-${{ github.ref }}
+  # Other branches: Shared group with cancel-in-progress to stop old runs when new commits are pushed
+  group: ${{ github.workflow }}-${{ github.ref }}-${{ github.ref == 'refs/heads/develop' && github.run_number || 'branch' }}
   cancel-in-progress: true
 
 jobs: