Add 1.91.1 patch release

Author: dtolnay

scripts/update-revs.sh

@@ -11,7 +11,7 @@ patch_releases=(
     1.12.1 1.15.1 1.22.1 1.24.1 1.26.1 1.26.2 1.27.1 1.27.2 1.29.1 1.29.2 1.30.1
     1.31.1 1.34.1 1.34.2 1.41.1 1.43.1 1.44.1 1.45.1 1.45.2 1.52.1 1.56.1 1.58.1
     1.62.1 1.66.1 1.67.1 1.68.1 1.68.2 1.71.1 1.72.1 1.74.1 1.77.1 1.77.2 1.80.1
-    1.84.1 1.85.1
+    1.84.1 1.85.1 1.91.1
 )
 
 releases() {