[bazel] Bump Bazel version to 6.2.1

Signed-off-by: Dan McArdle <[email protected]>

Author: dmcardle

.bazelversion

@@ -1 +1 @@
-5.1.1
+6.2.1

util/prep-bazel-airgapped-build.sh

@@ -141,6 +141,8 @@ if [[ ${AIRGAPPED_DIR_CONTENTS} == "ALL" || \
   ${BAZELISK} fetch \
     --repository_cache=${BAZEL_AIRGAPPED_DIR}/${BAZEL_CACHEDIR} \
     //... \
+    @remote_java_tools//... \
+    @remote_java_tools_linux//... \
     @bindgen_clang_linux//... \
     @rules_rust_bindgen__bindgen-0.60.1//... \
     @go_sdk//... \