devel/py-pytest-mock: Update to 1.10.4

• Conditionalise mock dependency (Python 2.x only)
• Add upstream patches to fix test failures with mock 3.x
• Verbosify test target and print skipped messages/reasons
• Pet portlint: NO_ARCH in USE/USES section

Changelog:

https://github.com/pytest-dev/pytest-mock/blob/1.10.4/CHANGELOG.rst

Reviewed by: olgeni
Approved by: olgeni (maintainer)
Differential Revision: D20167