fix: declare IOException in tearDown for Spark 4.x compile

`SparkSession.close()` throws checked `IOException` on Spark 4.x but
not on 3.x. The base test file is added to every version module's test
source set, so the missing `throws` clause broke `make test` on Spark
4.0/4.1.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Vova Kolmakov

docs/src/operations/dql/vector-search.md

@@ -9,7 +9,7 @@ Implemented as a **table-valued function**, so it composes cleanly with `WHERE`,
     [Spark SQL Extensions](../../config.md#spark-sql-extensions) for configuration details.
 
 !!! tip "Also see"
-    - [CREATE VECTOR INDEX](../ddl/create-vector-index.md) — build the index the search uses.
+    - [CREATE INDEX](../ddl/create-index.md) — build the vector (`ivf_*`) index the search uses.
     - [Select](select.md) — general read path.
 
 ## Syntax
@@ -84,7 +84,7 @@ smaller than `k` (or the pre-filter eliminates enough rows).
 
 ### `metric`
 Which distance metric to use. See the metric table in
-[CREATE VECTOR INDEX → Distance Metrics](../ddl/create-vector-index.md#distance-metrics).
+[CREATE INDEX → Distance Metrics](../ddl/create-index.md#distance-metrics).
 If omitted, the metric stored inside the index is used.
 
 ### `nprobes`

lance-spark-base_2.12/src/test/java/org/lance/spark/read/BaseLanceVectorSearchTest.java

@@ -75,7 +75,7 @@ public void setup() throws IOException {
   }
 
   @AfterEach
-  public void tearDown() {
+  public void tearDown() throws IOException {
     if (spark != null) {
       spark.close();
       spark = null;