Cleanup after ARM GPU runner (#1074)

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**Context:**
Currently Arm GPU CI runners may be reused between runs, and there is no
cleanup job after each runs. This means that caches/wheels from previous
runs contaminate later runs.

**Description of the Change:**
Clean cache after each Arm GPU CI runs. E.g.
[here](https://github.com/PennyLaneAI/pennylane-lightning/actions/runs/13593391314/job/38004671288?pr=1074#step:13:1)

**Benefits:**
No contamination between runs.

**Possible Drawbacks:**

**Related GitHub Issues:**

---------

Co-authored-by: ringo-but-quantum <[email protected]>

Author: josephleekl

.github/CHANGELOG.md

@@ -60,6 +60,9 @@
 
 ### Bug fixes
 
+* Fix Github CI for aarch64 cuda to clean up after runs.
+  [(#1074)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1074)
+
 * Increase maximum time for aarch64-CUDA Github CI action .
   [(#1070)](https://github.com/PennyLaneAI/pennylane-lightning/pull/1070)
 

.github/workflows/wheel_linux_aarch64_cuda.yml

@@ -142,6 +142,13 @@ jobs:
           retention-days: 1
           include-hidden-files: true
 
+      - name: Cleanup
+        if: always()
+        run: |
+          rm -rf ${{ steps.setup_venv.outputs.venv_name }}
+          rm -rf * .git .gitignore .github
+          pip cache purge
+
   upload-pypi:
     needs: [set_wheel_build_matrix, linux-wheels-aarch64]
     strategy:
@@ -168,3 +175,10 @@ jobs:
         with:
           verbose: true
           repository-url: https://test.pypi.org/legacy/
+
+      - name: Cleanup
+        if: always()
+        run: |
+          rm -rf ${{ steps.setup_venv.outputs.venv_name }}
+          rm -rf * .git .gitignore .github
+          pip cache purge