Bump semver from 7.5.1 to 7.5.4 in /demos/palm/node/pipet-code-agent (google#153)

Bumps [semver](https://github.com/npm/node-semver) from 7.5.1 to 7.5.4.
- [Release notes](https://github.com/npm/node-semver/releases)
- [Changelog](https://github.com/npm/node-semver/blob/main/CHANGELOG.md)
- [Commits](npm/node-semver@v7.5.1...v7.5.4)

---
updated-dependencies:
- dependency-name: semver
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]