Use docker compose V2 to cache downloaded packages

[EnricoMi]

Uses docker compose V2 and docker build cache mounts to speed up repeated docker builds.

See:

• https://docs.docker.com/compose/migrate/
• https://docs.docker.com/build/guide/mounts/

[github-actions]

Unit Test Results

   568 files   -   156    568 suites   - 156   6h 47m 49s ⏱️ - 1h 18m 18s
   887 tests ±    0    692 ✅  -    76    195 💤 + 76  0 ❌ ±0 
12 738 runs   - 3 471  8 641 ✅  - 2 712  4 097 💤  - 759  0 ❌ ±0 

Results for commit 0e8b71f. ± Comparison against base commit 9f88e1d.

This pull request skips 76 tests.

test.parallel.test_mxnet1.MX1Tests ‑ test_gluon_trainer
test.parallel.test_mxnet1.MX1Tests ‑ test_gpu_required
test.parallel.test_mxnet1.MX1Tests ‑ test_horovod_allreduce_cpu_gpu_error
test.parallel.test_mxnet1.MX1Tests ‑ test_horovod_grouped_allgather_cpu_gpu_error
test.parallel.test_mxnet1.MX1Tests ‑ test_horovod_grouped_allreduce_cpu_gpu_error
test.parallel.test_tensorflow.TensorFlowTests ‑ test_gpu_required
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_fused_gpu
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_gpu
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_grad_gpu
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_variable_size_fused_gpu
…

[github-actions]

Unit Test Results (with flaky tests)

   600 files   -   288    600 suites   - 288   6h 56m 29s ⏱️ - 2h 2m 12s
   887 tests ±    0    692 ✅  -    76    195 💤 +   76  0 ❌ ±0 
13 454 runs   - 6 785  9 037 ✅  - 4 752  4 417 💤  - 2 033  0 ❌ ±0 

Results for commit 0e8b71f. ± Comparison against base commit 9f88e1d.

This pull request skips 76 tests.

test.parallel.test_mxnet1.MX1Tests ‑ test_gluon_trainer
test.parallel.test_mxnet1.MX1Tests ‑ test_gpu_required
test.parallel.test_mxnet1.MX1Tests ‑ test_horovod_allreduce_cpu_gpu_error
test.parallel.test_mxnet1.MX1Tests ‑ test_horovod_grouped_allgather_cpu_gpu_error
test.parallel.test_mxnet1.MX1Tests ‑ test_horovod_grouped_allreduce_cpu_gpu_error
test.parallel.test_tensorflow.TensorFlowTests ‑ test_gpu_required
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_fused_gpu
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_gpu
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_grad_gpu
test.parallel.test_tensorflow.TensorFlowTests ‑ test_horovod_allgather_variable_size_fused_gpu
…