Upgrade python-patch to the latest upstream release

[fmarier]

This fixes brave/brave-browser#3932.

The version we were using was an svn import of code.google.com to GitHub but both code.google.com and the importer are now defunct:

http://piotr.gabryjeluk.pl/blog:closing-svn2github

The upstream developer, according to the PyPI project page (https://pypi.org/project/patch/), has moved to a dedicated repo on GitHub:

https://github.com/techtonik/python-patch

I picked the latest upstream release (1.16):

https://github.com/techtonik/python-patch/releases/tag/1.16
techtonik/python-patch@2148d54

as the commit to pin our dependency to since the only commits on master after that are related to a part of the package that we don't use and that has been moved to another package:

techtonik/python-patch@76f0205

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests && npm run test-security) on
  • Windows
  • macOS
  • Linux
• Verified that all lint errors/warnings are resolved (npm run lint)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone
• Public documentation has been updated as necessary. For instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protection-Mode
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-compatibility-issues-with-tracking-protection

Test Plan:

To test that the new version gives me the same output with our current patches, I did the following under the old version:

$ cd src
$ git reset --hard
HEAD is now at 97cde3a81abd Publish DEPS for 74.0.3729.91
$ cd ..
$ npm run apply_patches
...
$ npm run update_patches

which gave me the following diff in src/brave: https://gist.github.com/fmarier/7b127e6d2d6b2b6076f98d81202defe2

Then I applied and updated the patches again:

$ npm run apply_patches
...
$ npm run update_patches

and got the following diff: https://gist.github.com/fmarier/2899dfd116a02a17fa31a1131825f89c

which is in line with this known bug (also reported upstream).

I ran gclient sync and then tested applying the patches again.

I got the same results as above in the first and second runs.

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on.
• All relevant documentation has been updated.