Enable incremental typechecking for tsc

Regarding this merge request !11811 (merged) where @franklygeorge says that tsc doesn't have a way to cache results, unless I'm misunderstanding then this feature was added to TypeScript a few years ago in 3.4, though use together with noEmit wasn't added until 4.0.

• https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-4.html#faster-subsequent-builds-with-the---incremental-flag
• https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-0.html#--incremental-with---noemit

I've added the necessary options to enable it in tsconfig.json. Running on Linux, the first run before .tsbuildinfo is generated still takes a long time:

$ npx tsc --version
Version 5.5.3
$ time npx tsc
...
real    0m41.976s
user    1m3.159s
sys     0m1.337s

Subsequent runs after that however are much faster:

$ time npx tsc
...
real    0m8.488s
user    0m14.164s
sys     0m0.694s

I haven't checked the speed increase on Windows. 14 seconds is still a bit slow but there might not be a way around that.