chore: Remove killswitch CLI tool (#104261)

We no longer use this tool as killswitches can be set with
options-automator now.

Fixes STREAM-546

Author: markstory

src/sentry/runner/commands/killswitches.py

@@ -54,7 +54,6 @@ def cli(config: str) -> None:
         "sentry.runner.commands.files.files",
         "sentry.runner.commands.help.help",
         "sentry.runner.commands.init.init",
-        "sentry.runner.commands.killswitches.killswitches",
         "sentry.runner.commands.migrations.migrations",
         "sentry.runner.commands.plugins.plugins",
         "sentry.runner.commands.repair.repair",