fix bash lint

Author: YiMysty

entrypoint.sh

@@ -37,7 +37,7 @@ else
   FUTURE=''
 fi
 
-cd "$PAGES_GEM_HOME"
+{ cd "$PAGES_GEM_HOME" || { echo "::error::pages gem not found"; exit 1; }; }
 
 # Run the command, capturing the output
 build_output="$($GITHUB_PAGES_BIN build "$VERBOSE" "$FUTURE" --source "$SOURCE_DIRECTORY" --destination "$DESTINATION_DIRECTORY")"