gradlew: no "--source 11" (#13404)

* avoid WrapperDownloader if have the JAR
* don't specify --source
More specific than needed, and some JDK/configs may complain about an incompatibility with --release.

From apache/solr#2419

gradlew

@@ -157,21 +157,23 @@ if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
 fi
 
 GRADLE_WRAPPER_JAR="$APP_HOME/gradle/wrapper/gradle-wrapper.jar"
-"$JAVACMD" $JAVA_OPTS --source 11 "$APP_HOME/buildSrc/src/main/java/org/apache/lucene/gradle/WrapperDownloader.java" "$GRADLE_WRAPPER_JAR"
-WRAPPER_STATUS=$?
-if [ "$WRAPPER_STATUS" -eq 1 ]; then
-    echo "ERROR: Something went wrong. Make sure you're using Java 11 or later."
-    exit $WRAPPER_STATUS
-elif [ "$WRAPPER_STATUS" -ne 0 ]; then
-    exit $WRAPPER_STATUS
+if [ ! -e "$GRADLE_WRAPPER_JAR" ]; then
+    "$JAVACMD" $JAVA_OPTS "$APP_HOME/buildSrc/src/main/java/org/apache/lucene/gradle/WrapperDownloader.java" "$GRADLE_WRAPPER_JAR"
+    WRAPPER_STATUS=$?
+    if [ "$WRAPPER_STATUS" -eq 1 ]; then
+        echo "ERROR: Something went wrong. Make sure you're using Java 11 or later."
+        exit $WRAPPER_STATUS
+    elif [ "$WRAPPER_STATUS" -ne 0 ]; then
+        exit $WRAPPER_STATUS
+    fi
 fi
 
 CLASSPATH=$GRADLE_WRAPPER_JAR
 
 # START OF LUCENE CUSTOMIZATION
 # Generate gradle.properties if they don't exist
 if [ ! -e "$APP_HOME/gradle.properties" ]; then
-    "$JAVACMD" $JAVA_OPTS --source 11 "$APP_HOME/buildSrc/src/main/java/org/apache/lucene/gradle/GradlePropertiesGenerator.java" "$APP_HOME/gradle/template.gradle.properties" "$APP_HOME/gradle.properties"
+    "$JAVACMD" $JAVA_OPTS "$APP_HOME/buildSrc/src/main/java/org/apache/lucene/gradle/GradlePropertiesGenerator.java" "$APP_HOME/gradle/template.gradle.properties" "$APP_HOME/gradle.properties"
     GENERATOR_STATUS=$?
     if [ "$GENERATOR_STATUS" -ne 0 ]; then
         exit $GENERATOR_STATUS

gradlew.bat

@@ -75,9 +75,11 @@ goto fail
 
 @rem LUCENE-9266: verify and download the gradle wrapper jar if we don't have one.
 set GRADLE_WRAPPER_JAR=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
-"%JAVA_EXE%" %JAVA_OPTS% --source 11 "%APP_HOME%/buildSrc/src/main/java/org/apache/lucene/gradle/WrapperDownloader.java" "%GRADLE_WRAPPER_JAR%"
-IF %ERRORLEVEL% EQU 1 goto failWithJvmMessage
-IF %ERRORLEVEL% NEQ 0 goto fail
+IF NOT EXIST "%GRADLE_WRAPPER_JAR%" (
+    "%JAVA_EXE%" %JAVA_OPTS% "%APP_HOME%/buildSrc/src/main/java/org/apache/lucene/gradle/WrapperDownloader.java" "%GRADLE_WRAPPER_JAR%"
+    IF %ERRORLEVEL% EQU 1 goto failWithJvmMessage
+    IF %ERRORLEVEL% NEQ 0 goto fail
+)
 
 @rem Setup the command line
 set CLASSPATH=%GRADLE_WRAPPER_JAR%
@@ -87,7 +89,7 @@ set CLASSPATH=%GRADLE_WRAPPER_JAR%
 IF NOT EXIST "%APP_HOME%\gradle.properties" (
   @rem local expansion is needed to check ERRORLEVEL inside control blocks.
   setlocal enableDelayedExpansion
-  "%JAVA_EXE%" %JAVA_OPTS% --source 11 "%APP_HOME%/buildSrc/src/main/java/org/apache/lucene/gradle/GradlePropertiesGenerator.java" "%APP_HOME%\gradle\template.gradle.properties" "%APP_HOME%\gradle.properties"
+  "%JAVA_EXE%" %JAVA_OPTS% "%APP_HOME%/buildSrc/src/main/java/org/apache/lucene/gradle/GradlePropertiesGenerator.java" "%APP_HOME%\gradle\template.gradle.properties" "%APP_HOME%\gradle.properties"
   IF %ERRORLEVEL% NEQ 0 goto fail
   endlocal
 )