[SPARK-46382][SQL] XML: Update doc for ignoreSurroundingSpaces

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

Update doc for `ignoreSurroundingSpaces`

### Why are the changes needed?

Be aligned with the implementation

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

Yes

### How was this patch tested?

This is a doc-only change

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

No

Closes #44671 from shujingyang-db/ignore-surronding-space-doc.

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

Author: shujingyang-db

docs/sql-data-sources-xml.md

@@ -128,7 +128,7 @@ Data source options of XML can be set via:
 
   <tr>
     <td><code>ignoreSurroundingSpaces</code></td>
-    <td><code>false</code></td>
+    <td><code>true</code></td>
     <td>Defines whether surrounding whitespaces from values being read should be skipped.</td>
     <td>read</td>
   </tr>