Add experimental support for 'cache-write-only'

There may be cases where it a "fresh" cache entry would be beneficial,
for example if the Gradle User Home cache entry grows over time.

This setting would run the build as if no prior cache entry exists.

action.yml

@@ -50,6 +50,10 @@ inputs:
   # The following action properties allow fine-grained tweaking of the action caching behaviour.
   # These properties are experimental and not (yet) designed for production use, and may change without notice in a subsequent release of `gradle-build-action`.
   # Use at your own risk!
+  cache-write-only:
+    description: When 'true', entries will not be restored from the cache but will be saved at the end of the Job. This allows a 'clean' cache entry to be written.
+    required: false
+    default: false
   gradle-home-cache-strict-match:
     description: When 'true', the action will not attempt to restore the Gradle User Home entries from other Jobs.
     required: false