[release] install regex (#30008)

Signed-off-by: Kevin H. Luu <khluu000@gmail.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

.buildkite/scripts/upload-wheels.sh

@@ -81,7 +81,7 @@ else
     alias_arg=""
 fi
 
-$PYTHON .buildkite/scripts/generate-nightly-index.py --version "$SUBPATH" --current-objects "$obj_json" --output-dir "$INDICES_OUTPUT_DIR" $alias_arg
+$PYTHON pip install regex && .buildkite/scripts/generate-nightly-index.py --version "$SUBPATH" --current-objects "$obj_json" --output-dir "$INDICES_OUTPUT_DIR" $alias_arg
 
 # copy indices to /<commit>/ unconditionally
 echo "Uploading indices to $S3_COMMIT_PREFIX"