Added restoreCacheKeys so cache.restoreCache will restore closest match

That way running pre-commit should only update envs that need changing.
If the restored cache doesn't match the cacheKey exactly (python version or config changed), it will try to save the envs  with the new cacheKey to cache.

index.js

@@ -51,9 +51,10 @@ async function main() {
     const cachePaths = [path.join(os.homedir(), '.cache', 'pre-commit')];
     const py = getPythonVersion();
     const cacheKey = `pre-commit-2-${hashString(py)}-${hashFile('.pre-commit-config.yaml')}`;
-    const restored = await cache.restoreCache(cachePaths, cacheKey);
+    const restoreCacheKeys = [`pre-commit-2-${hashString(py)}-`, "pre-commit-2-"];
+    const restored = await cache.restoreCache(cachePaths, cacheKey, restoreCacheKeys);
     const ret = await exec.exec('pre-commit', args, {ignoreReturnCode: push});
-    if (!restored) {
+    if (restored !== cacheKey) {
         try {
             await cache.saveCache(cachePaths, cacheKey);
         } catch (e) {