Backport Bugzilla 2053518: Rust target detection fails to translate the host triple with rustc nightly >= 2026-07-02 (new *-oe-linux-* targets)

⬅️ Backport Patchset

Bookkeeping

Issue(s)

• tor-browser#xxxxx
• mullvad-browser#xyz
• https://bugzilla.mozilla.org/show_bug.cgi?id=2053518

Merge Request(s)

• tor-browser!xxxx
• 1ecaa128

Target Channels

• Alpha
• Stable

Notes

After updating Rust to 1.98 I wasn't able to build Firefox anymore.

I've asked upstream to uplift this, but in the meantime if we could backport this downstream it'd help me.

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