[Cherry-pick] Fix v2 transforms in spawn mp context (#8067)

[NicolasHug]

Cherry-pick of #8067

cc @pmeier @vfdev-5

[pytorch-bot]

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✅ You can merge normally! (27 Unrelated Failures)

As of commit db96b8e with merge base f1b4c7a ():

FLAKY - The following jobs failed but were likely due to flakiness present on trunk:

• CMake / linux (linux.12xlarge, cpu) / linux-job (gh)
• CMake / linux (linux.g5.4xlarge.nvidia.gpu, cuda, 11.8) / linux-job (gh)
• CMake / macos (macos-12) / macos-job (gh)
• CMake / macos (macos-m1-12) / macos-job (gh)
• CMake / windows (windows.4xlarge, cpu) / windows-job (gh)
• CMake / windows (windows.g5.4xlarge.nvidia.gpu, cuda, 11.8) / windows-job (gh)
• Docs / build / linux-job (gh)
• Lint / c-source / linux-job (gh)
• Lint / python-source-and-configs / linux-job (gh)
• Lint / python-types / linux-job (gh)
• Tests / onnx / linux-job (gh)
• Tests / unittests-extended / linux-job (gh)
• Tests / unittests-linux (3.10, linux.12xlarge, cpu) / linux-job (gh)
• Tests / unittests-linux (3.11, linux.12xlarge, cpu) / linux-job (gh)
• Tests / unittests-linux (3.8, linux.12xlarge, cpu) / linux-job (gh)
• Tests / unittests-linux (3.8, linux.g5.4xlarge.nvidia.gpu, cuda, 11.8) / linux-job (gh)
• Tests / unittests-linux (3.9, linux.12xlarge, cpu) / linux-job (gh)
• Tests / unittests-macos (3.10, macos-12) / macos-job (gh)
• Tests / unittests-macos (3.11, macos-12) / macos-job (gh)
• Tests / unittests-macos (3.8, macos-12) / macos-job (gh)
• Tests / unittests-macos (3.8, macos-m1-12) / macos-job (gh)
• Tests / unittests-macos (3.9, macos-12) / macos-job (gh)
• Tests / unittests-windows (3.10, windows.4xlarge, cpu) / windows-job (gh)
• Tests / unittests-windows (3.11, windows.4xlarge, cpu) / windows-job (gh)
• Tests / unittests-windows (3.8, windows.4xlarge, cpu) / windows-job (gh)
• Tests / unittests-windows (3.8, windows.g5.4xlarge.nvidia.gpu, cuda, 11.8) / windows-job (gh)
• Tests / unittests-windows (3.9, windows.4xlarge, cpu) / windows-job (gh)

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[vfdev-5]

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