Add automatic generation of .latexminted_config to Makefile

[alexkeizer]

This incorporates the setup notes regarding minted 3's configuration file into the Makefile, so that no more manual setup steps are required.

In particular:

• We add a Makefile recipe for the .latexminted_config file in the current directory, and
• We check for the existence of ~/.latexminted_config and raise an error if it doesn't
  • The error points to a new script which can be used to auto-generate this config, too, but I didn't want to pollute the home-dir without explicit prompting from the user
  • Note that we only check for the existence of the global config file; we don't check whether the necessary "enable_cwd_config" option is actually set when the file is already present. The latter could be doable using jq, but I didn't want to assume that is installed.
• Finally, we tweak the CI to run the Makefile to generate the .latexminted_config file at least (CI does not seem to be using the Makefile to generate the pdfs, which is why this wasn't happening automatically yet, but I have no desire to touch that right now).
  • Note that we removed the latexminted_config file from the repository, and added it to .gitignore, since it ought to be automatically generated anyway.

[alexkeizer]

Hmm, CI currently fails with the following error:

 ./paper.tex:703: Package minted Error: 
 => ./paper:594: Custom lexer "MLIRLexer.py" is not enabled in ".latexminted_co
nfig"; check that SHA-256 hash is present and updated.

I wonder, does CI use the Makefile from the PR branch, or from somewhere else? The generation of the relevant config file seems to work perfectly, locally

[bollu]

Conceptually LGTM, but please make sure the script is clean as per shellcheck.

[alexkeizer]

CI is now happy, with some tweaks:

Finally, we tweak the CI to run the Makefile to generate the .latexminted_config file at least (CI does not seem to be using the Makefile to generate the pdfs, which is why this wasn't happening automatically yet, but I have no desire to touch that right now).

• Note that we removed the latexminted_config file from the repository, and added it to .gitignore, since it ought to be automatically generated anyway.