Fix deprecation warnings

[azeey]

🦟 Bug fix

Summary

Fix deprecation warnings:

• Replace avcodec_close with avcodec_free_context
• Suppress deprecation of std::iterator since we can't change it without breaking ABI. I only did this for macOS, since that's the only platform that emits the warning.

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
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[scpeters]

this change causes a test failure on 20.04; perhaps we can ifdef on the software version if we can figure out the difference in the version variables between 20.04 and 22.04?

[azeey]

I didn't do much investigation into whether we can simply replace avcodec_close with avcodec_free_context, but let me try it on a newer version of Ubuntu to see if it fails everywhere.

[azeey]

Looking at this more closely, I think it's more about how codecCtx was created in the first place. In d38e4d3, I've used avcodec_free_context if codeCtx was created using avcodec_alloc_context3, which is inline with the ffmpeg documentation