[CI] Remove a few predefined runner files before releasing npm packages (#2775)

## Motivation for the change, related issues

Updates the publish-npm-packages.yml job to prevent the CI runner from
running out of disk space.


https://github.com/WordPress/wordpress-playground/actions/runs/18473424159/job/52632469981

```
lerna ERR! 
lerna ERR! lerna ENOSPC: no space left on device, write
```

## Implementation details

Removes a bunch of large files that seem to be present at the start of
the job:

```
            - name: Free up runner disk space
              shell: bash
              run: |
                  set -euo pipefail
                  echo "Disk usage before cleanup:"
                  df -h
                  sudo rm -rf /usr/local/lib/android
                  sudo rm -rf /usr/share/dotnet
                  sudo rm -rf "$AGENT_TOOLSDIRECTORY"
                  sudo rm -rf /opt/ghc
                  sudo rm -rf /opt/hostedtoolcache/CodeQL
                  echo "Disk usage after cleanup:"
                  df -h
```

## Testing Instructions (or ideally a Blueprint)

GitHub and testing CI PRs? Haha. Nope. Merge, run the job, hope for the
best.

Author: adamziel

.github/workflows/publish-npm-packages.yml

@@ -37,6 +37,19 @@ jobs:
             NPM_TOKEN: ${{ secrets.NPM_AUTOMATION_TOKEN }}
             GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         steps:
+            - name: Free up runner disk space
+              shell: bash
+              run: |
+                  set -euo pipefail
+                  echo "Disk usage before cleanup:"
+                  df -h
+                  sudo rm -rf /usr/local/lib/android
+                  sudo rm -rf /usr/share/dotnet
+                  sudo rm -rf "$AGENT_TOOLSDIRECTORY"
+                  sudo rm -rf /opt/ghc
+                  sudo rm -rf /opt/hostedtoolcache/CodeQL
+                  echo "Disk usage after cleanup:"
+                  df -h
             - uses: actions/checkout@v4
               with:
                   ref: ${{ github.event.pull_request.head.ref }}