Bump image_optim_pack from 0.12.1.20250704 to 0.12.1.20250921

Bumps [image_optim_pack](https://github.com/toy/image_optim_pack) from 0.12.1.20250704 to 0.12.1.20250921.
- [Changelog](https://github.com/toy/image_optim_pack/blob/main/CHANGELOG.markdown)
- [Commits](toy/image_optim_pack@v0.12.1.20250704...v0.12.1.20250921)

---
updated-dependencies:
- dependency-name: image_optim_pack
  dependency-version: 0.12.1.20250921
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -143,10 +143,10 @@ GEM
       image_size (>= 1.5, < 4)
       in_threads (~> 1.3)
       progress (~> 3.0, >= 3.0.1)
-    image_optim_pack (0.12.1.20250704)
+    image_optim_pack (0.12.1.20250921)
       fspath (>= 2.1, < 4)
       image_optim (~> 0.19)
-    image_optim_pack (0.12.1.20250704-x86_64-linux)
+    image_optim_pack (0.12.1.20250921-x86_64-linux)
       fspath (>= 2.1, < 4)
       image_optim (~> 0.19)
     image_size (3.4.0)