fix: Don't use deps dir for non-cached builds

[mildaniel]

Why is this change necessary?

After accelerate GA, we stopped gating the creating of a dependencies dir with a feature flag which means that now a dependencies dir is used for all builds where applicable. This means that the downstream lambda builders workflow performs an accelerate-specific workflow even when it shouldn't.

How does it address the issue?

Don't build with dependencies dir if cached is False.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[qingchm]

LGTM, wondering if the appbuilder parameter should just be called cached or using_dependencies_dir

[qingchm]

Let's address the test failures before merging:
for windows: tests/unit/lib/build_module/test_app_builder.py::TestApplicationBuilder_build::test_must_not_use_dep_layer_for_non_cached
for linux and windows: tests/unit/lib/build_module/test_build_strategy.py::DefaultBuildStrategyTest::test_build_layers_and_functions

[mildaniel]

LGTM, wondering if the appbuilder parameter should just be called cached or using_dependencies_dir

Happy to switch it to cached. Might be better if we decide to use it for other things in the future.