feat!: add cache service v2, add toolkit patches (#1110)

Serves `github.actions.results.api.v1.CacheService` next to the v1 cache API, sharing its store, plus the subset of the Azure blob protocol the toolkit uploads with. On by default via `cache.v2`, and works with `external_server`.

Clients reach it through two edits in the action's own bundle: the GHES check is opened, and the cache service URL is taken from `ACTIONS_CACHE_URL`.

The same GHES check is what makes the stock `actions/upload-artifact` and `download-artifact` abort on Gitea. Opening it makes them work without the `gitea-upload-artifact` fork, from `[email protected]` on.

Verified against 118 real bundles, every major version of 16 actions: 92 patched, the rest deliberately left alone, and every patched bundle checked with `node --check`. Also end to end against pinned `actions/[email protected]` with an unreachable results URL, so only the patch can make the cache work.

---------

Co-authored-by: silverwind <[email protected]>
Co-authored-by: bircni <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1110
Reviewed-by: silverwind <[email protected]>

act/artifactcache/handler_test.go

@@ -1041,14 +1041,14 @@ func TestHandler_SecretPersistsAcrossRestarts(t *testing.T) {
 	first, err := StartHandler(dir, "127.0.0.1", 0, "", nil)
 	require.NoError(t, err)
 	exp := time.Now().Add(artifactURLTTL).Unix()
-	sig := first.computeSignature(42, exp)
+	sig := first.computeSignature("", 42, exp)
 	require.NoError(t, first.Close())
 
 	second, err := StartHandler(dir, "127.0.0.1", 0, "", nil)
 	require.NoError(t, err)
 	defer second.Close()
 
-	assert.Equal(t, sig, second.computeSignature(42, exp))
+	assert.Equal(t, sig, second.computeSignature("", 42, exp))
 }
 
 // TestHandler_ArtifactSignatureDownload is a happy-path round trip that