Update hippomocks

[hexagonrecursion]

• Obsoletes The macOS-12 environment is deprecated #1791
• Possibly fixes Hippomocks doesn't support arm64 or any mips* #853

1. Remove the macos-12 runner because guthub no longer supports if
2. Add macos-14 and macos-15 runners
3. Update hippomocks to a version that appears to support ARM64
4. Re-apply our custom fix to make hippomocks support c++20

An alternative solution would be to use gMock - an actively maintained mocking framework that is already included in the testing framework we are using.

[hexagonrecursion]

Re-apply our custom fix to make hippomocks support c++20

• Now that Adapt C++ change N4152 if detected. dascandy/hippomocks#115 has been merged our custom fix is probably unnecessary - we can use take hippomocks directly from upstream