NXP backend: Extend unittest-nxp-neutron job timeout to 120 minutes. (#20332)

### Summary
This is a temporary fix to enable our workflow. A propper fix (test
parallelism) is currently being worked on.

### Test plan
N/A


cc @robert-kalmar @JakeStevens @digantdesai @rascani

Author: MartinPavella

.github/workflows/pull.yml

@@ -1400,7 +1400,7 @@ jobs:
       docker-image: ci-image:executorch-ubuntu-22.04-clang12
       submodules: 'recursive'
       ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-      timeout: 90
+      timeout: 120
       script: |
         set -eux