Gemfile.lock: update sorbet-runtime to match sorbet

[Bo98]

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This normally would have happened automatically in #10532, but the vendor-gems workflow was disabled at the time.

#10586 covers this, but this PR will likely get merged much quicker since the new Sorbet version contains breaking changes (the plugin system we rely on is gone).

[BrewTestBot]

Review period will end on 2021-02-15 at 03:25:39 UTC.

[BrewTestBot]

Review period will end on 2021-02-15 at 03:25:39 UTC.

[BrewTestBot]

Review period skipped due to critical label.

[MikeMcQuaid]

Thanks @Bo98