Remove unused dynamo import

[NicolasHug]

Following up on my confusion from #8436 (comment), @ezyang can you confirm that prior to this PR we weren't taking advantage of the "lazy import"? (Otherwise, I still don't get the point of lazy_compile)

[pytorch-bot]

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❌ 3 New Failures, 2 Unrelated Failures

As of commit f4bf776 with merge base 375cfdf ():

NEW FAILURES - The following jobs have failed:

• Tests / unittests-macos (3.11, macos-m1-stable) / macos-job (gh)
  The process '/usr/bin/git' failed with exit code 128
• Tests / unittests-macos (3.9, macos-m1-stable) / macos-job (gh)
  The process '/usr/bin/git' failed with exit code 128
• Tests / unittests-windows (3.11, windows.4xlarge, cpu) / windows-job (gh)
  The process 'C:\Program Files\Git\cmd\git.exe' failed with exit code 128

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

• Tests / unittests-linux (3.11, linux.12xlarge, cpu) / linux-job (gh) (matched linux rule in flaky-rules.json)
  The process '/usr/bin/git' failed with exit code 128
• Tests / unittests-linux (3.12, linux.12xlarge, cpu) / linux-job (gh) (matched linux rule in flaky-rules.json)
  The process '/usr/bin/git' failed with exit code 128

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[ezyang]

looks like it works