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.

src/cache-utils.ts

@@ -9,6 +9,7 @@ import {CacheEntryListener} from './cache-reporting'
 const JOB_CONTEXT_PARAMETER = 'workflow-job-context'
 const CACHE_DISABLED_PARAMETER = 'cache-disabled'
 const CACHE_READONLY_PARAMETER = 'cache-read-only'
+const CACHE_WRITEONLY_PARAMETER = 'cache-write-only'
 const CACHE_DEBUG_VAR = 'GRADLE_BUILD_ACTION_CACHE_DEBUG_ENABLED'
 const CACHE_PREFIX_VAR = 'GRADLE_BUILD_ACTION_CACHE_KEY_PREFIX'
 
@@ -20,6 +21,10 @@ export function isCacheReadOnly(): boolean {
     return core.getBooleanInput(CACHE_READONLY_PARAMETER)
 }
 
+export function isCacheWriteOnly(): boolean {
+    return core.getBooleanInput(CACHE_WRITEONLY_PARAMETER)
+}
+
 export function isCacheDebuggingEnabled(): boolean {
     return process.env[CACHE_DEBUG_VAR] ? true : false
 }