Rollup merge of #103660 - ozkanonur:master, r=jyn514

improve `filesearch::get_or_default_sysroot`

`fn get_or_default_sysroot` is now improved and used in `miri` and `clippy`, and tests are still passing as they should. So we no longer need to implement custom workarounds/hacks to find sysroot in tools like miri/clippy.

Resolves https://github.com/rust-lang/rust/issues/98832

re-opened from #103581

diff --cc Cargo.lock
Simple merge

diff --cc compiler/rustc_codegen_ssa/src/back/link.rs
Simple merge

diff --cc compiler/rustc_session/src/config.rs
Simple merge

diff --cc compiler/rustc_session/src/session.rs
Simple merge

diff --cc src/tools/clippy/src/driver.rs
Simple merge