Upgrade maven to 3.9.9 and wrapper to 3.3.2

and add .gitattributes in case people don't have core.autocrlf set

cmd: `mvn wrapper:wrapper -Dmaven=3.9.9`

Author: sepe81

.mvn/wrapper/maven-wrapper.properties

@@ -14,5 +14,6 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.6/apache-maven-3.9.6-bin.zip
-wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.2.0/maven-wrapper-3.2.0.jar
+wrapperVersion=3.3.2
+distributionType=only-script
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.9/apache-maven-3.9.9-bin.zip