Bump phpstan/extension-installer from 1.4.2 to 1.4.3 (#668)

Bumps [phpstan/extension-installer](https://github.com/phpstan/extension-installer) from 1.4.2 to 1.4.3.
- [Release notes](https://github.com/phpstan/extension-installer/releases)
- [Commits](phpstan/extension-installer@1.4.2...1.4.3)

---
updated-dependencies:
- dependency-name: phpstan/extension-installer
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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