Remove the check for the NPM 6 cafile in .npmrc

[markhallen]

What are you trying to accomplish?

This is a follow-up to #11302

It seems that this spec should have failed, but it didn't because CI used a cached docker container.

Anything you want to highlight for special attention from reviewers?

The spec is now redundant as we have removed the assignment for the NPM 6 cafile in .npmrc.

How will you know you've accomplished your goal?

We can recreate the issue:

1. On the main branch run bin/docker-dev-shell npm_and_yarn --rebuild
2. Run the spec in the container cd npm_and_yarn && rspec ./spec/npm_and_yarn_config_spec.rb
3. The spec should fail ❌
4. Revert the commit fromhttps://github.com/Remove cafile hack used for NPM 6 #11302, git revert cf69f2537e5fab87a40acdeaad362d7a84042da6
5. Run bin/docker-dev-shell npm_and_yarn --rebuild
6. Run the spec in the container cd npm_and_yarn && rspec ./spec/npm_and_yarn_config_spec.rb
7. The spec should pass ✅

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.