[release/8.0.1xx-xcode16.0] [build] Fix installing the arm64 version of .NET.

[vs-mobiletools-engineering-service2]

On the bots we're executing with Rosetta, and 'arch' returns 'i386' under
Rosetta, so detect when we're executing under Rosetta, and install the arm64
version of .NET in that case as well.

Also fix a bug in the same area in our tests.

Backport of #21396

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS X64 - Mac Sonoma (14) passed 💻

✅ All tests on macOS X64 - Mac Sonoma (14) passed.

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Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS M1 - Mac Monterey (12) passed 💻

✅ All tests on macOS M1 - Mac Monterey (12) passed.

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Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS M1 - Mac Big Sur (11) passed 💻

✅ All tests on macOS M1 - Mac Big Sur (11) passed.

Pipeline on Agent
Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Tests on macOS M1 - Mac Ventura (13) passed 💻

✅ All tests on macOS M1 - Mac Ventura (13) passed.

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Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

📚 [CI Build] Artifacts 📚

Artifacts were not provided.

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Hash: [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Windows Integration Tests passed 💻

✅ All Windows Integration Tests passed.

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Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

💻 [CI Build] Windows Integration Tests passed 💻

✅ All Windows Integration Tests passed.

Pipeline on Agent
Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

✅ API diff for current PR / commit

NET (empty diffs)

• iOS: (empty diff detected)
• tvOS: (empty diff detected)
• MacCatalyst: (empty diff detected)
• macOS: (empty diff detected)

✅ API diff vs stable

.NET (No breaking changes)

• iOS: vsdrops gist (No breaking changes)
• tvOS: vsdrops gist (No breaking changes)
• MacCatalyst: vsdrops gist (No breaking changes)
• macOS: vsdrops gist (No breaking changes)

ℹ️ Generator diff

Generator Diff: vsdrops (html) vsdrops (raw diff) gist (raw diff) - Please review changes)

Pipeline on Agent
Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]

[vs-mobiletools-engineering-service2]

🚀 [CI Build] Test results 🚀

Test results

✅ All tests passed on VSTS: test results.

🎉 All 97 tests passed 🎉

Tests counts

✅ cecil: All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (iOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (MacCatalyst): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (macOS): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (Multiple platforms): All 1 tests passed. Html Report (VSDrops) Download
✅ dotnettests (tvOS): All 1 tests passed. Html Report (VSDrops) Download
✅ framework: All 2 tests passed. Html Report (VSDrops) Download
✅ fsharp: All 4 tests passed. Html Report (VSDrops) Download
✅ generator: All 1 tests passed. Html Report (VSDrops) Download
✅ interdependent-binding-projects: All 4 tests passed. Html Report (VSDrops) Download
✅ introspection: All 4 tests passed. Html Report (VSDrops) Download
✅ linker: All 40 tests passed. Html Report (VSDrops) Download
✅ monotouch (iOS): All 7 tests passed. Html Report (VSDrops) Download
✅ monotouch (MacCatalyst): All 7 tests passed. Html Report (VSDrops) Download
✅ monotouch (macOS): All 8 tests passed. Html Report (VSDrops) Download
✅ monotouch (tvOS): All 7 tests passed. Html Report (VSDrops) Download
✅ msbuild: All 2 tests passed. Html Report (VSDrops) Download
✅ xcframework: All 4 tests passed. [attempt 2] Html Report (VSDrops) Download
✅ xtro: All 1 tests passed. Html Report (VSDrops) Download

Pipeline on Agent
Hash: 4c8717f50e94e48697d5eccbab59f52e15754fc4 [PR build]