test(vector-search): size guard-test query vectors to the resolved index dimension

The branch's new up-front query-dimension guard validates every query
against the vector column's dimension before planning and before the
empty-plan early return. For an ARRAY<FLOAT> IVF_FLAT column with no
explicit dimension, the resolver defaults to 128, so the dim-1 query
vectors (`vec![1.0]`) in two guard tests failed loud before reaching the
guards they exercise:

  - execute_read_empty_plan_reserved_projection_fails_loud
  - execute_read_filter_with_deletion_vectors_passes_guard

Pin `fields.embedding.dimension = 4` and size the query vectors to match,
so each test reaches its reserved-projection / deletion-vector residual
guard as intended. Test-only; production behavior is unchanged.

Author: lijunrui

crates/paimon/src/table/vector_search_builder.rs

@@ -4512,12 +4512,15 @@ mod tests {
             ("fields.embedding.pk-vector.index.type", IVF_FLAT_IDENTIFIER),
             ("fields.embedding.pk-vector.distance.metric", "l2"),
             ("deletion-vectors.enabled", "true"),
+            // Pin the index dimension so the query vector below matches it; the
+            // up-front dimension guard runs before this test's residual guard.
+            ("fields.embedding.dimension", "4"),
         ]);
         let filter = id_gt_filter(&table, 2);
         let mut stream = table
             .new_vector_search_builder()
             .with_vector_column("embedding")
-            .with_query_vector(vec![1.0])
+            .with_query_vector(vec![1.0; 4])
             .with_limit(5)
             .with_filter(filter)
             .execute_read()
@@ -4939,6 +4942,10 @@ mod tests {
             ("pk-vector.index.columns", "embedding"),
             ("fields.embedding.pk-vector.index.type", IVF_FLAT_IDENTIFIER),
             ("fields.embedding.pk-vector.distance.metric", "l2"),
+            // Pin the index dimension so the query vector below matches it; the
+            // up-front dimension guard runs before this test's reserved-projection
+            // guard, so a mismatched query would mask the error under test.
+            ("fields.embedding.dimension", "4"),
         ]);
         for reserved in [
             ROW_ID_FIELD_NAME,
@@ -4949,7 +4956,7 @@ mod tests {
             let mut builder = table.new_vector_search_builder();
             builder
                 .with_vector_column("embedding")
-                .with_query_vector(vec![1.0])
+                .with_query_vector(vec![1.0; 4])
                 .with_limit(5)
                 .with_projection(&["id", reserved]);
             let err = builder