[SPARK-48763][TESTS][FOLLOW-UP] Update project location in PlanGenerationTestSuite

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

This PR is a followup of #47579 that updates the Spark Connect location in the test `PlanGenerationTestSuite`.

### Why are the changes needed?

Just for completeness.

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

No, test-only.

### How was this patch tested?

Manually ran it via:

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

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

No.

Closes #47605 from HyukjinKwon/SPARK-48763-followup2.

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

Author: HyukjinKwon

connector/connect/client/jvm/src/test/scala/org/apache/spark/sql/PlanGenerationTestSuite.scala

@@ -92,6 +92,8 @@ class PlanGenerationTestSuite
   // with the datasource.
   protected val testDataPath: Path = java.nio.file.Paths.get(
     "../",
+    "sql",
+    "connect",
     "common",
     "src",
     "test",

sql/connect/common/src/test/resources/query-tests/queries/read.json

@@ -10,7 +10,7 @@
         "header": "true",
         "delimiter": ";"
       },
-      "paths": ["../common/src/test/resources/query-tests/test-data/people.csv"]
+      "paths": ["../sql/connect/common/src/test/resources/query-tests/test-data/people.csv"]
     }
   }
 }

sql/connect/common/src/test/resources/query-tests/queries/read.proto.bin

@@ -5,7 +5,7 @@
   "read": {
     "dataSource": {
       "format": "csv",
-      "paths": ["../common/src/test/resources/query-tests/test-data/people.csv"]
+      "paths": ["../sql/connect/common/src/test/resources/query-tests/test-data/people.csv"]
     }
   }
 }

sql/connect/common/src/test/resources/query-tests/queries/read_csv.json

@@ -5,7 +5,7 @@
   "read": {
     "dataSource": {
       "format": "json",
-      "paths": ["../common/src/test/resources/query-tests/test-data/people.json"]
+      "paths": ["../sql/connect/common/src/test/resources/query-tests/test-data/people.json"]
     }
   }
 }

sql/connect/common/src/test/resources/query-tests/queries/read_csv.proto.bin

@@ -5,7 +5,7 @@
   "read": {
     "dataSource": {
       "format": "orc",
-      "paths": ["../common/src/test/resources/query-tests/test-data/users.orc"]
+      "paths": ["../sql/connect/common/src/test/resources/query-tests/test-data/users.orc"]
     }
   }
 }

sql/connect/common/src/test/resources/query-tests/queries/read_json.json

@@ -5,7 +5,7 @@
   "read": {
     "dataSource": {
       "format": "parquet",
-      "paths": ["../common/src/test/resources/query-tests/test-data/users.parquet"]
+      "paths": ["../sql/connect/common/src/test/resources/query-tests/test-data/users.parquet"]
     }
   }
 }