docs: Add release notes for prefect-kubernetes==0.7.7 (#21434)

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Nate Nowack <nate@prefect.io>

Author: devin-ai-integration[bot]

docs/v3/release-notes/integrations/prefect-kubernetes.mdx

@@ -2,6 +2,17 @@
 title: prefect-kubernetes
 ---
 
+## 0.7.7
+
+_Released on April 06, 2026_
+
+**Bug Fixes**
+
+- Preserve casing of Kubernetes label keys [#21259](https://github.com/PrefectHQ/prefect/pull/21259) by [@app/devin-ai-integration](https://github.com/app/devin-ai-integration)
+- Fix ambiguous `kopf` jobs selector by scoping resource selector to `batch/v1` [#21209](https://github.com/PrefectHQ/prefect/pull/21209) by [@bdalpe](https://github.com/bdalpe)
+
+---
+
 ## 0.7.6
 
 _Released on March 19, 2026_