[SPARK-34774][BUILD] Ensure change-scala-version.sh update scala.version in parent POM correctly

### What changes were proposed in this pull request?
After SPARK-34507,  execute` change-scala-version.sh` script will update `scala.version` in parent pom, but if we execute the following commands in order：

```
dev/change-scala-version.sh 2.13
dev/change-scala-version.sh 2.12
git status
```

there will generate git diff as follow:

```
diff --git a/pom.xml b/pom.xml
index ddc4ce2..f43d8c8f78 100644
--- a/pom.xml
+++ b/pom.xml
 -162,7 +162,7
     <commons.math3.version>3.4.1</commons.math3.version>

     <commons.collections.version>3.2.2</commons.collections.version>
-    <scala.version>2.12.10</scala.version>
+    <scala.version>2.13.5</scala.version>
     <scala.binary.version>2.12</scala.binary.version>
     <scalatest-maven-plugin.version>2.0.0</scalatest-maven-plugin.version>
     <scalafmt.parameters>--test</scalafmt.parameters>
```

seem 'scala.version' property was not update correctly.

So this pr add an extra 'scala.version' to scala-2.12 profile to ensure change-scala-version.sh can update the public `scala.version` property correctly.

### Why are the changes needed?
Bug fix.

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
**Manual test**

Execute the following commands in order：

```
dev/change-scala-version.sh 2.13
dev/change-scala-version.sh 2.12
git status
```

**Before**

```
diff --git a/pom.xml b/pom.xml
index ddc4ce2..f43d8c8f78 100644
--- a/pom.xml
+++ b/pom.xml
 -162,7 +162,7
     <commons.math3.version>3.4.1</commons.math3.version>

     <commons.collections.version>3.2.2</commons.collections.version>
-    <scala.version>2.12.10</scala.version>
+    <scala.version>2.13.5</scala.version>
     <scala.binary.version>2.12</scala.binary.version>
     <scalatest-maven-plugin.version>2.0.0</scalatest-maven-plugin.version>
     <scalafmt.parameters>--test</scalafmt.parameters>
```

**After**

No git diff.

Closes #31865 from LuciferYang/SPARK-34774.

Authored-by: yangjie01 <[email protected]>
Signed-off-by: Sean Owen <[email protected]>

Author: LuciferYang

pom.xml

@@ -3306,6 +3306,13 @@
 
     <profile>
       <id>scala-2.12</id>
+      <properties>
+        <!-- 
+         SPARK-34774 Add this property to ensure change-scala-version.sh can replace the public `scala.version`
+         property correctly. 
+        -->
+        <scala.version>2.12.10</scala.version>
+      </properties>
       <build>
         <pluginManagement>
           <plugins>