Add Oauth workflow scope

Grants the ability to add and update GitHub Actions workflow files.

Bug: Issue 14533
Change-Id: I7d8b937b46af92341a34843ed87e9ba987f228bf

github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java

diff --git a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java
index 6e4d500..b93837b 100644
--- a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java
+++ b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/OAuthProtocol.java
@@ -134,7 +134,10 @@
     WRITE_PUBLIC_KEY("write:public_key", "Read/write/list owned public keys"),
 
     /** Fully manage public keys. */
-    ADMIN_PUBLIC_KEY("admin:public_key", "Fully manage owned public keys");
+    ADMIN_PUBLIC_KEY("admin:public_key", "Fully manage owned public keys"),
+
+    /** Grants the ability to add and update GitHub Actions workflow files. */
+    WORKFLOW("workflow", "Manage actions workflow files.");
 
     @Getter private final String value;