fix find -perm syntax for linux in release workflow

Author: perkee

.github/workflows/homebrew-release.yml

@@ -70,7 +70,7 @@ jobs:
         run: |
           BIN=$(cabal -v0 list-bin elm-format)
           if [ ! -f "$BIN" ]; then
-            BIN=$(find dist-newstyle -name elm-format -type f -perm +111 | head -1)
+            BIN=$(find dist-newstyle -name elm-format -type f -executable | head -1)
           fi
           mkdir staging
           cp "$BIN" staging/elm-format