[ci] Ensure that TF does not preempt all GPU memory for itself

see https://www.tensorflow.org/guide/gpu#limiting_gpu_memory_growth

Co-Authored-By: Funtowicz Morgan <mfuntowicz@users.noreply.github.com>
Co-Authored-By: Lysandre Debut <lysandre.debut@reseau.eseo.fr>

.github/workflows/self-push.yml

@@ -40,6 +40,7 @@ jobs:
 
     - name: Run all non-slow tests on GPU
       env:
+        TF_FORCE_GPU_ALLOW_GROWTH: yes
         OMP_NUM_THREADS: 1
         USE_CUDA: yes
       run: |

.github/workflows/self-scheduled.yml

@@ -41,6 +41,7 @@ jobs:
 
     - name: Run all tests on GPU
       env:
+        TF_FORCE_GPU_ALLOW_GROWTH: yes
         OMP_NUM_THREADS: 1
         RUN_SLOW: yes
         USE_CUDA: yes