Update PVC storage to 3Gi

While performing the release,
the gorelease task failed with the
error failed to write xxx no space left on device.
To resolve this issue increased the PVC storage.

Signed-off-by: Savita Ashture <[email protected]>

.tekton/release-pipeline.yaml

@@ -137,4 +137,4 @@ spec:
             - ReadWriteOnce
           resources:
             requests:
-              storage: 1Gi
+              storage: 3Gi