Its rare to get walked out, even if going to a competitor.
And unless the OP was on a performance plan or in a lower bucket of ratings (which doesn't sound like it's the case as they're being asked to become a TL), they would not be counted as "unregretted attrition".
First, make sure you don't have too many personal belongings in the office. There's always a chance they'll walk you out of the building on the spot.
Second, tell your manager that you think it's time for a change in your life, and you plan to move on from the company. Your manager probably has an "unregretted attrition" target, so they're unlikely to object to a 2-week notice period if they aren't spiteful.
You will take a big salary hit - make your peace with not owning a downtown penthouse by age 40 - but you probably have enough of a cushion to spend 6-12 months taking stock of your life and goals.
It's not so bad.