[SPARK-31258][BUILD] Pin the avro version in SBT

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

add arvo dep in SparkBuild

### Why are the changes needed?
fix sbt unidoc like #28017 (comment)
```scala
[warn] Multiple main classes detected.  Run 'show discoveredMainClasses' to see the list
[warn] Multiple main classes detected.  Run 'show discoveredMainClasses' to see the list
[info] Main Scala API documentation to /home/jenkins/workspace/SparkPullRequestBuilder6/target/scala-2.12/unidoc...
[info] Main Java API documentation to /home/jenkins/workspace/SparkPullRequestBuilder6/target/javaunidoc...
[error] /home/jenkins/workspace/SparkPullRequestBuilder6/core/src/main/scala/org/apache/spark/serializer/GenericAvroSerializer.scala:123: value createDatumWriter is not a member of org.apache.avro.generic.GenericData
[error]     writerCache.getOrElseUpdate(schema, GenericData.get.createDatumWriter(schema))
[error]                                                         ^
[info] No documentation generated with unsuccessful compiler run
[error] one error found
```

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

no
### How was this patch tested?

pass jenkins
and verify manually with `sbt dependencyTree`
```scala
 kentyaohulk  ~/spark   dep  build/sbt dependencyTree | grep avro | grep -v Resolving
[info]   +-org.apache.avro:avro-mapred:1.8.2
[info]   | +-org.apache.avro:avro-ipc:1.8.2
[info]   | | +-org.apache.avro:avro:1.8.2
[info]   +-org.apache.avro:avro:1.8.2
[info]   | | +-org.apache.avro:avro:1.8.2
[info] org.apache.spark:spark-avro_2.12:3.1.0-SNAPSHOT [S]
[info]   | | | +-org.apache.avro:avro-mapred:1.8.2
[info]   | | | | +-org.apache.avro:avro-ipc:1.8.2
[info]   | | | | | +-org.apache.avro:avro:1.8.2
[info]   | | | +-org.apache.avro:avro:1.8.2
[info]   | | | | | +-org.apache.avro:avro:1.8.2
```

Closes #28020 from yaooqinn/dep.

Authored-by: Kent Yao <[email protected]>
Signed-off-by: HyukjinKwon <[email protected]>
(cherry picked from commit 336621e)
Signed-off-by: HyukjinKwon <[email protected]>

Author: yaooqinn

project/SparkBuild.scala

@@ -624,7 +624,8 @@ object DependencyOverrides {
     dependencyOverrides += "com.google.guava" % "guava" % "14.0.1",
     dependencyOverrides += "commons-io" % "commons-io" % "2.4",
     dependencyOverrides += "xerces" % "xercesImpl" % "2.12.0",
-    dependencyOverrides += "jline" % "jline" % "2.14.6")
+    dependencyOverrides += "jline" % "jline" % "2.14.6",
+    dependencyOverrides += "org.apache.avro" % "avro" % "1.8.2")
 }
 
 /**