[FLINK-36181] Remove Scala version bump for Java11 and Java17 profiles

Since we've bumped Scala all together, we no longer need to bump it for these profiles

pom.xml

@@ -1069,8 +1069,6 @@ under the License.
 			</activation>
 
 			<properties>
-				<!-- Bump Scala because 2.12.7 doesn't compile on Java 17. -->
-				<scala.version>2.12.20</scala.version>
 				<surefire.excludedGroups.jdk>org.apache.flink.testutils.junit.FailsOnJava17</surefire.excludedGroups.jdk>
 			</properties>
 
@@ -1126,11 +1124,6 @@ under the License.
 				<jdk>[21,)</jdk>
 			</activation>
 
-			<properties>
-				<!-- Bump Scala because before 2.12.7 doesn't compile on Java 21. -->
-				<scala.version>2.12.20</scala.version>
-			</properties>
-
 			<build>
 				<pluginManagement>
 					<plugins>