Automatic toolchain upgrade to nightly-2025-09-23

[github-actions]

Update Rust toolchain from nightly-2025-09-22 to nightly-2025-09-23 without any other source changes.

[github-actions]

This is an automatically generated pull request. If any of the CI checks fail,
manual intervention is required. In such a case, review the changes at
https://github.com/rust-lang/rust from
rust-lang/rust@9f32ccf up to
rust-lang/rust@f6092f2. The log
for this commit range is:

https://github.com/rust-lang/rust/commit/f6092f224d Auto merge of #146892 - GuillaumeGomez:rollup-fa7lp0n, r=GuillaumeGomez

rust-lang/rust@9814d08545 Rollup merge of #146887 - taiki-e:rc-doc-feature, r=joboet
rust-lang/rust@4852e692cd Rollup merge of #146884 - Kobzol:tidy-rustdoc-modified, r=GuillaumeGomez
rust-lang/rust@090befc5e0 Rollup merge of #146848 - moturus:motor-os_tier-3, r=davidtwco
rust-lang/rust@de7065b7d8 Rollup merge of #146828 - el-ev:issue146646, r=GuillaumeGomez
rust-lang/rust@dc176bd216 Rollup merge of #146795 - alexcrichton:wasm-limit-rdylib-exports, r=bjorn3
rust-lang/rust@ce4beebecb Auto merge of #146683 - clarfonthey:safe-intrinsics, r=RalfJung,Amanieu
rust-lang/rust@823337a4ad Remove unused #![feature(get_mut_unchecked)] in Rc and Arc examples
rust-lang/rust@870a98c7b3 Fix modification check of rustdoc-json-types
rust-lang/rust@29005cb128 Auto merge of #146879 - Zalathar:rollup-vm97j8b, r=Zalathar
rust-lang/rust@8f80707bc5 Rollup merge of #146878 - RalfJung:check_language_ub, r=tgross35
rust-lang/rust@a5e1ab590b Rollup merge of #146858 - Gelbpunkt:mips64el-musl-dynamic, r=jieyouxu
rust-lang/rust@8cf94b6c82 Rollup merge of #146846 - hkBst:btree-2, r=tgross35
rust-lang/rust@7b6553c746 Rollup merge of #146845 - Zalathar:prof-target-machine, r=Kobzol
rust-lang/rust@681da13a02 Rollup merge of #146838 - yotamofek:pr/rustdoc/wrappers, r=lolbinarycat
rust-lang/rust@46be365a60 Rollup merge of #146831 - taiki-e:powerpc-clobber, r=Amanieu
rust-lang/rust@40db498a0f Rollup merge of #146791 - folkertdev:readonly-not-pure, r=nikic,joshtriplett
rust-lang/rust@d144638f89 Rollup merge of #146397 - pthariensflame:patch-1, r=Amanieu
rust-lang/rust@8c0c53791b Rollup merge of #145411 - the8472:cows-have-no-branches, r=Mark-Simulacrum
rust-lang/rust@7d0012914e assert_unsafe_precondition: fix some incorrect check_language_ub