Speedup main CI

[muellerzr]

Speed up main GitHub CI

What does this add?

This PR speeds up the time for the github CI tests to pass by ~2.5x through a few basic optimizations:

Adjustments to the Makefile

Four new test conditionals were added to the Makefile based on groupings of how each example test needs to be ran, and how their topics relate to each other:

• test_example_differences: The quick method that checks if the .py files are missing any parts in the examples/ dir
• test_checkpoint_step: tests relating to checkpoint by step and load checkpoint by step
• test_checkpoint_epoch: tests relating to checkpoint by epoch and loading checkpoint by epoch
• test_rest: Everything that did not fall under the previous three

Use setup-python@v3 and cache@v3

By using these two specific actions, we can speed up the time it takes to setup the python environment, cache the pip installation, and also cache the model downloads.

Total Speedup

• Main tests: 2m42s -> 1m16s (~2x speedup)
• Example tests: 9m5s -> ~(3m47s, 4m20s) (~2.1-2.4x speedup)
  (This also counts as the overall time taken)

Without the cache, it's ~8.5 minutes on that first commit/run.

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[sgugger]

Very nice speed-up, thanks a lot!