MIPS targets are broken on nightly channel

[spvkgn]

2024-12-29T08:47:25.5907051Z info: syncing channel updates for 'nightly-x86_64-unknown-linux-gnu'
2024-12-29T08:47:25.6339646Z warning: Signature verification failed for 'https://static.rust-lang.org/dist/channel-rust-nightly.toml'
2024-12-29T08:47:25.6711106Z info: latest update on 2024-12-29, rust version 1.85.0-nightly (8742e0556 2024-12-28)
2024-12-29T08:47:25.6711678Z info: downloading component 'cargo'
2024-12-29T08:47:25.7152525Z info: downloading component 'rust-std'
2024-12-29T08:47:25.8292888Z info: downloading component 'rustc'
2024-12-29T08:47:26.1192741Z info: installing component 'cargo'
2024-12-29T08:47:26.7446170Z info: installing component 'rust-std'
2024-12-29T08:47:28.7374239Z info: installing component 'rustc'
2024-12-29T08:47:32.9659953Z 
2024-12-29T08:47:32.9757613Z   nightly-x86_64-unknown-linux-gnu installed - rustc 1.85.0-nightly (8742e0556 2024-12-28)
2024-12-29T08:47:32.9758509Z 
2024-12-29T08:47:32.9759860Z info: checking for self-updates
2024-12-29T08:47:32.9791099Z info: downloading self-update
2024-12-29T08:47:33.1328246Z error: component 'rust-std' for target 'mipsel-unknown-linux-musl' is unavailable for download for channel 'nightly'
2024-12-29T08:47:33.1329587Z Sometimes not all components are available in any given nightly. 

rust-lang/compiler-team#648