feat: add support for reproducible builds

[kruskall]

Add support for SOURCE_DATE_EPOCH to avoid timestamp and timezones
issues.

See https://reproducible-builds.org/specs/source-date-epoch/

Make sure zip entries have a consistent mtime and strip extra
attributes.

See https://reproducible-builds.org/docs/archives/

Zip archives are now reproducible by default. Update script
to use the make task and avoid calling zip directly.

For more information see https://reproducible-builds.org/

[ghost]

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• Start Time: 2022-07-20T14:26:50.280+0000

• Duration: 16 min 51 sec

Test stats 🧪

Test	Results
Failed	0
Passed	224
Skipped	4
Total	228

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[axw]

Nice, I wasn't aware of that spec. Looks good, just wondering if we should set a different default in the Makefile.

[axw]

Lovely, thanks!