fix(runtime): Restore default signal handler after user handlers are unregistered (#22757)

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Fixes #22724. Fixes #7164.

This does add a dependency on `signal-hook`, but it's just a higher
level API on top of `signal-hook-registry` (which we and `tokio` already
depend on) and doesn't add any transitive deps.

0 files changed, 0 insertions, 0 deletions