Bump pillow-heif from 0.16.0 to 0.18.0

Bumps [pillow-heif](https://github.com/bigcat88/pillow_heif) from 0.16.0 to 0.18.0.
- [Release notes](https://github.com/bigcat88/pillow_heif/releases)
- [Changelog](https://github.com/bigcat88/pillow_heif/blob/master/CHANGELOG.md)
- [Commits](bigcat88/pillow_heif@v0.16.0...v0.18.0)

---
updated-dependencies:
- dependency-name: pillow-heif
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -142,7 +142,7 @@ pillow==10.1.0
     # via
     #   -r requirements.in
     #   pillow-heif
-pillow-heif==0.16.0
+pillow-heif==0.18.0
     # via -r requirements.in
 pint==0.23
     # via datasette