Add @llvm_flirtool//... to airgap image

Bypass-Presubmit-Reason: tested manually
Change-Id: I22760365407b31796f624fddb4140bba7279481a

util/prep-bazel-airgapped-build.sh

diff --git a/util/prep-bazel-airgapped-build.sh b/util/prep-bazel-airgapped-build.sh
index 905771e..8e0e08a 100755
--- a/util/prep-bazel-airgapped-build.sh
+++ b/util/prep-bazel-airgapped-build.sh
@@ -205,7 +205,8 @@
     @rust_analyzer_1.67.0_tools//... \
     @rust_linux_x86_64__x86_64-unknown-linux-gnu__nightly_tools//... \
     @org_chipsalliance_chisel_plugin//... \
-    @kelvin_hw//lib:chisel_lib
+    @kelvin_hw//lib:chisel_lib \
+    @llvm_firtool//...
   cp -R $(${BAZEL_AIRGAPPED_DIR}/bazel info output_base)/external/${BAZEL_PYTHON_WHEEL_REPO} \
     ${BAZEL_AIRGAPPED_DIR}/
   echo "Done."