Update on "[Executorch] Add quantized kv cache to oss ci"

Fixes to make sure quantized kv cache works in oss

Differential Revision: [D66269487](https://our.internmc.facebook.com/intern/diff/D66269487/)

[ghstack-poisoned]

Author: kimishpatel

.ci/scripts/test_llama.sh

@@ -113,7 +113,6 @@ if [[ "${MODE}" =~ .*qnn.* ]]; then
   export EXECUTORCH_ROOT="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
   export QNN_SDK_ROOT=/tmp/qnn/2.25.0.240728
   export LD_LIBRARY_PATH="${QNN_SDK_ROOT}/lib/x86_64-linux-clang"
-  export PYTHONPATH=".."
   cp schema/program.fbs exir/_serialize/program.fbs
   cp schema/scalar_type.fbs exir/_serialize/scalar_type.fbs
   cp -f build-x86/backends/qualcomm/PyQnnManagerAdaptor.cpython-310-x86_64-linux-gnu.so backends/qualcomm/python