Automatic toolchain upgrade to nightly-2026-01-04

[github-actions]

Update Rust toolchain from nightly-2026-01-03 to nightly-2026-01-04 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@85c8ff6 up to
rust-lang/rust@7ecabfa. The log
for this commit range is:

https://github.com/rust-lang/rust/commit/7ecabfaaf1 Auto merge of #150639 - usamoi:stdarch, r=sayantn

rust-lang/rust@1d22b964df Auto merge of #150644 - matthiaskrgr:rollup-ey900sr, r=matthiaskrgr
rust-lang/rust@1fe83d5b91 Rollup merge of #150641 - joboet:netbsd-bindings, r=tgross35
rust-lang/rust@01141eae58 Rollup merge of #145339 - Ayush1325:uefi-tcp4-accept, r=tgross35
rust-lang/rust@0e5a4fb302 std: remove manual bindings on NetBSD
rust-lang/rust@4c3310a6db Auto merge of #150638 - matthiaskrgr:rollup-924nozj, r=matthiaskrgr
rust-lang/rust@689e74d944 Rollup merge of #150637 - vsriramv:fix/edit-url-template, r=Kobzol
rust-lang/rust@f7d67d7b92 Rollup merge of #150635 - tgross35:float-format-parse-mention, r=jieyouxu
rust-lang/rust@cd502ff78e Rollup merge of #150589 - AprilNEA:remove-unneeded-forbid-generic-field, r=camelid,BoxyUwU
rust-lang/rust@7af208fe0b Rollup merge of #150570 - Human9000-bit:main, r=jieyouxu
rust-lang/rust@78376fd39c Rollup merge of #150558 - estebank:multiple-dep-versions, r=jieyouxu
rust-lang/rust@d79fa3ca3d Fixed edit-url-template by pointing to main instead of HEAD in both unstable book and the rustc book
rust-lang/rust@00f49d2204 Auto merge of #145948 - a4lg:riscv-stabilize-target-features-v2, r=Amanieu
rust-lang/rust@a8c23c86f0 triagebot: Add a mention for dec2flt, flt2dec, and fmt/num
rust-lang/rust@50d59402bf Auto merge of #150633 - JonathanBrouwer:rollup-lfp28cm, r=JonathanBrouwer
rust-lang/rust@d00729b4ba Rollup merge of #150632 - tshepang:rdg-sync, r=tshepang
rust-lang/rust@e75d14917d Rollup merge of #150627 - Coca162:without_provenance_diagnostics, r=Urgau
rust-lang/rust@085d6b81b3 Merge pull request #2717 from rust-lang/rustc-pull
rust-lang/rust@874cbe6836 Merge ref '85c8ff69cb3e' from rust-lang/rust
rust-lang/rust@e8f3cfc0de Auto merge of #150628 - JonathanBrouwer:rollup-zy040xr, r=JonathanBrouwer