Now that concurrent inlining is shipping on stable, remove support
--no-concurrent-inlining.

Note that it's still possible to run Turbofan exclusively on the
main thread by passing --no-concurrent-recompilation.

Bug: v8:7790, v8:12142, chromium:1240585
Change-Id: I1943bbbcad7dea7e3a3c337c239f14f7d96c23cd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3308798Reviewed-by: Liviu Rau <liviurau@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78644}