update-python-resources: add option to ignore errors

[gromgit]

This is particularly useful for third-party Python formulae that have a ton of resources, not all of which may adhere to homebrew/core's strict policies. See #19240 for context.

I've also added logic that ignores --ignore-errors on homebrew/core, although I personally think this new behavior is also useful for mainline formula creation.

Before: error out on a single non-conforming resource, zero resource blocks added to formula, scary stacktrace (in debug mode).

After: all conforming resources added, all non-conforming resources identified in comments, error message at end, brew exits non-zero without scary stacktrace:-

% brew update-python-resources --ignore-errors gromgit/test/auto-coder || echo OOPS
==> Retrieving PyPI dependencies for "auto-coder==0.1.243"...
==> Retrieving PyPI dependencies for excluded ""...
==> Getting PyPI info for "aiohappyeyeballs==2.4.4"
[200+ resource lines elided]
==> Getting PyPI info for "zhipuai==2.1.5.20250106"
==> Updating resource blocks
Error: Unable to resolve some dependencies. Please check /opt/homebrew/Library/Taps/gromgit/homebrew-test/Formula/auto-coder.rb for RESOURCE-ERROR comments.
OOPS

% brew cat gromgit/test/auto-coder | ggrep -C10 RESOURCE-ERROR
  license "Apache-2.0"

  depends_on "python@3.11"

  # Additional dependency
  # resource "" do
  #   url ""
  #   sha256 ""
  # end

  # RESOURCE-ERROR: Unable to resolve "azure-cognitiveservices-speech==1.42.0" (no suitable source distribution on PyPI)
  # RESOURCE-ERROR: Unable to resolve "ray==2.42.0" (no suitable source distribution on PyPI)

  resource "aiohappyeyeballs" do
    url "https://files.pythonhosted.org/packages/7f/55/e4373e888fdacb15563ef6fa9fa8c8252476ea071e96fb46defac9f18bf2/aiohappyeyeballs-2.4.4.tar.gz"
    sha256 "5fdd7d87889c63183afc18ce9271f9b0a7d32c2303e394468dd45d514a757745"
  end

  resource "aiohttp" do
    url "https://files.pythonhosted.org/packages/37/4b/952d49c73084fb790cb5c6ead50848c8e96b4980ad806cf4d2ad341eaa03/aiohttp-3.11.12.tar.gz"
    sha256 "7603ca26d75b1b86160ce1bbe2787a0b706e592af5b2504e12caa88a217767b0"
  end

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• Have you successfully run brew style with your changes locally?
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• Have you successfully run brew tests with your changes locally?

[MikeMcQuaid]

Makes sense to me, thanks @gromgit!

Only thing before merging: I'd almost be tempted to say this should be default behaviour? Thoughts @cho-m and @woodruffw?

[woodruffw]

LGTM overall! My 0.02c is that this should be non-default since it results in a non-functional formula definition (well-formed, but won't run correctly due to missing deps that need to be fixed manually).

OTOH we could make it the default, but add an audit rule that detects RESOURCE-ERROR: and fails the CI. No strong opinions either way 🙂