BugFix: fix detected_architecture() for Apple M1

[SSE4]

related: #8113

uname -m returns arm64 on Apple M1 https://stackoverflow.com/questions/65259300/detect-apple-silicon-from-command-line
/cc @theodelrieu

Changelog: BugFix: Fix detected_architecture() for Apple M1, mapping to armv8 (from returned arm64).
Docs: omit

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