chore(main): Release 0.1.21 (#204)

🤖 Automated Release PR

This PR was created by `release-please` to prepare the next release.
Once merged:

1. A new version tag will be created
2. A GitHub release will be published
3. The changelog will be updated

Changes to be included in the next release:
---


##
[0.1.21](0.1.20...0.1.21)
(2026-01-23)


### Features

* Add support for masks in `regrid` filter
([#108](#108))
([89d5214](89d5214))


### Bug Fixes

* Add `patch_data_request` to some filters
([#203](#203))
([22abaf7](22abaf7))
* Remove `variable` key in `GroupByParamVertical`
([#202](#202))
([b3e338b](b3e338b))

---
> [!IMPORTANT]
> Please do not change the PR title, manifest file, or any other
automatically generated content in this PR unless you understand the
implications. Changes here can break the release process.
> ⚠️ Merging this PR will:
> - Create a new release
> - Trigger deployment pipelines
> - Update package versions

 **Before merging:**
 - Ensure all tests pass
 - Review the changelog carefully
 - Get required approvals

[Release-please
documentation](https://github.com/googleapis/release-please)

Author: DeployDuck

.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-    ".": "0.1.20"
+    ".": "0.1.21"
 }

CHANGELOG.md

@@ -9,6 +9,19 @@ Please add your functional changes to the appropriate section in the PR.
 Keep it human-readable, your future self will thank you!
 
 
+## [0.1.21](https://github.com/ecmwf/anemoi-transform/compare/0.1.20...0.1.21) (2026-01-23)
+
+
+### Features
+
+* Add support for masks in `regrid` filter ([#108](https://github.com/ecmwf/anemoi-transform/issues/108)) ([89d5214](https://github.com/ecmwf/anemoi-transform/commit/89d521430744ddafdb285a645ff2d4ac02b47e05))
+
+
+### Bug Fixes
+
+* Add `patch_data_request` to some filters ([#203](https://github.com/ecmwf/anemoi-transform/issues/203)) ([22abaf7](https://github.com/ecmwf/anemoi-transform/commit/22abaf7547b7357bae5b280e1422302c2d040c00))
+* Remove `variable` key in `GroupByParamVertical` ([#202](https://github.com/ecmwf/anemoi-transform/issues/202)) ([b3e338b](https://github.com/ecmwf/anemoi-transform/commit/b3e338b9efe281754459249078104b57ec13b903))
+
 ## [0.1.20](https://github.com/ecmwf/anemoi-transform/compare/0.1.19...0.1.20) (2026-01-15)