Update metadata.yaml for next release (#327)

Signed-off-by: yiannistri <8741709+yiannistri@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

metadata.yaml

@@ -33,3 +33,6 @@ releaseSeries:
   - major: 0
     minor: 11
     contract: v1beta1
+  - major: 0
+    minor: 12
+    contract: v1beta1