Install Composer dependencies in release script

[pfefferle]

Fixes #

Proposed changes:

• Add composer run release step to install production-only Composer dependencies before building a release commit.
• Force-add vendor/ (which is gitignored) so production dependencies are included in the release branch.
• Restore dev dependencies after the release commit so the working tree remains usable.

Other information:

• Have you written new tests for your changes, if applicable?

Testing instructions:

• Run node bin/release.js and verify the release commit includes the vendor/ directory with only production dependencies.
• After the script completes, verify dev dependencies are restored locally.

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Patch

Type

• Fixed - for any bug fixes

Message

Install production Composer dependencies before building release packages.