[CI] Remove a few predefined runner files before releasing npm packages

[adamziel]

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.