docs(python): Document sys.exit integration

Add documentation for the sys.exit integration, introduced in getsentry/sentry-python#3401.

Closes #11043

Author: szokeasaurusrex

docs/platforms/python/integrations/index.mdx

@@ -110,6 +110,7 @@ The Sentry SDK uses integrations to hook into the functionality of popular libra
 | <LinkWithPlatformIcon platform="python.pure_eval"     label="Enhanced Locals" url="/platforms/python/integrations/pure_eval" />     |                  |
 | <LinkWithPlatformIcon platform="python.gnu_backtrace" label="GNU Backtrace"   url="/platforms/python/integrations/gnu_backtrace" /> |                  |
 | <LinkWithPlatformIcon platform="python.socket"        label="Socket"          url="/platforms/python/integrations/socket" />        |                  |
+| <LinkWithPlatformIcon platform="python.sys_exit"      label="sys.exit"        url="/platforms/python/integrations/sys_exit" />      |                  |
 | <LinkWithPlatformIcon platform="python.tryton"        label="Tryton"          url="/platforms/python/integrations/tryton" />        |                  |
 | <LinkWithPlatformIcon platform="python.wsgi"          label="WSGI"            url="/platforms/python/integrations/wsgi" />          |                  |