Docs for clang-format 19 (#13762)

CONTRIBUTING.md

@@ -132,7 +132,7 @@ To develop Firebase software, **install**:
    To install [clang-format] and [mint] using [Homebrew]:
 
     ```console
-    brew install clang-format@18
+    brew install clang-format@19
     brew install mint
     ```
 

README.md

@@ -153,7 +153,7 @@ GitHub Actions will verify that any code changes are done in a style-compliant
 way. Install `clang-format` and `mint`:
 
 ```console
-brew install clang-format@18
+brew install clang-format@19
 brew install mint
 ```
 

scripts/style.sh

@@ -65,7 +65,7 @@ case "$version" in
     exit 1
     ;;
   *)
-    echo "Please upgrade to clang-format version 18."
+    echo "Please upgrade to clang-format version 19."
     echo "If it's installed via homebrew you can run:"
     echo "brew upgrade clang-format"
     exit 1