[MINOR][SQL] Remove orphans in ProtoToParsedPlanTestSuite and PlanGenerationTestSuite

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

This PR proposes to remove orphans in ProtoToParsedPlanTestSuite and PlanGenerationTestSuite

### Why are the changes needed?

To remove unused files.

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

No.

### How was this patch tested?

Generated by below

```bash
SPARK_CLEAN_ORPHANED_GOLDEN_FILES=1 build/sbt "connect-client-jvm/testOnly org.apache.spark.sql.PlanGenerationTestSuite"
SPARK_CLEAN_ORPHANED_GOLDEN_FILES=1 build/sbt "connect/testOnly org.apache.spark.sql.connect.ProtoToParsedPlanTestSuite"
```

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

No.

Closes #47603 from HyukjinKwon/minor-cleanup-orphans.

Authored-by: Hyukjin Kwon <[email protected]>
Signed-off-by: Hyukjin Kwon <[email protected]>

Author: HyukjinKwon