chore: add v7 migration entry for bouncy castle

Signed-off-by: Marc Nuri <[email protected]>

doc/MIGRATION-v7.md

@@ -1,10 +1,18 @@
 # Migration from 6.x to 7.x
 
 ## Contents
+- [Bouncy Castle is no longer needed](#bouncy-castle)
 
 
 > [!NOTE]
 > If you encounter any problems with the following "Migration from 6.x to 7.x" instructions, please let us know by creating an issue in our [GitHub repository](https://github.com/fabric8io/kubernetes-client/issues).
 >
 > We value your feedback and will work to address your issue promptly.
 > Your contribution is essential to improving our documentation, making our migration process smoother for everyone!
+
+
+## Bouncy Castle is no longer needed <a href="#bouncy-castle" id="bouncy-castle"/>
+
+The Bouncy Castle library is no longer needed as a dependency.
+In previous versions, this was an optional dependency needed for Elliptic Curve (EC) Keys.
+The Kubernetes client now uses the default Java security provider which should be enough to handle all scenarios.