Action installs dependencies at runtime

[ekohl]

Currently the action installs its dependencies at runtime:

vale-action/src/input.ts

Lines 54 to 58 in 3a4769d

	await exec.exec('pip', ['install', 'docutils']);
	logIfDebug('`pip install docutils` complete');
	await exec.exec('gem', ['install', 'asciidoctor', '--user-install']);
	logIfDebug('`gem install asciidoctor --user-install` complete');

Then it also installs Vale and Reviewdog in https://github.com/errata-ai/vale-action/blob/reviewdog/src/install.ts.

This makes the action slower than it needs to be and also causes issues like #111 and #128.

My suggestion would be to start using an image that contains all the required dependencies. https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-docker-container-action describes this process. That's pretty much the opposite of 87aaef6. Sadly there's no PR attached to that commit with any explanation why this new strategy was used.

[jdkato]

Vale and Reviewdog are runtime dependencies in so much as their versions are configurable.

Using Docker (even a pre-built image) for the other 2 is not faster.