CI: bumped ST version to 4121.

Author: azizk

.github/workflows/main.yml

@@ -22,6 +22,6 @@ jobs:
       - uses: actions/checkout@v2
       - uses: SublimeText/syntax-test-action@v2
         with:
-          build: 4113
-          default_packages: v4113
+          build: 4121
+          default_packages: v4121
           package_name: ElixirSyntax