[MINOR][DOCS] Add zstandard as a candidate to fix the desc of spark.sql.avro.compression.codec

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

Add zstandard as a candidate to fix the desc of spark.sql.avro.compression.codec

### Why are the changes needed?

docfix

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

no

### How was this patch tested?

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

no

Closes #44783 from yaooqinn/avro_minor.

Authored-by: Kent Yao <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>
(cherry picked from commit c040824)
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: yaooqinn

docs/sql-data-sources-avro.md

@@ -348,7 +348,7 @@ Configuration of Avro can be done using the `setConf` method on SparkSession or
     <td>snappy</td>
     <td>
       Compression codec used in writing of AVRO files. Supported codecs: uncompressed, deflate,
-      snappy, bzip2 and xz. Default codec is snappy.
+      snappy, bzip2, xz and zstandard. Default codec is snappy.
     </td>
     <td>2.4.0</td>
   </tr>