[SPARK-47046][BUILD][TESTS] Upgrade mysql-connector-j to 9.0.0

### What changes were proposed in this pull request?

This PR aims to upgrade `mysql-connector-j` from 8.4.0 to 9.0.0.

### Why are the changes needed?

Version 9.0.0 is a new GA release version and is recommended for use. The full release notes of `mysql-connector-j` 9.0.0:
https://dev.mysql.com/doc/relnotes/connector-j/en/news-9-0-0.html

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Pass GA.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #47200 from wayneguow/upgrade_mysql_connector.

Authored-by: Wei Guo <guow93@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

pom.xml

@@ -323,7 +323,7 @@
       -Dio.netty.tryReflectionSetAccessible=true
     </extraJavaTestArgs>
     <mariadb.java.client.version>2.7.12</mariadb.java.client.version>
-    <mysql.connector.version>8.4.0</mysql.connector.version>
+    <mysql.connector.version>9.0.0</mysql.connector.version>
     <postgresql.version>42.7.3</postgresql.version>
     <db2.jcc.version>11.5.9.0</db2.jcc.version>
     <mssql.jdbc.version>12.6.2.jre11</mssql.jdbc.version>