Rollup merge of #142304 - Enselic:panic-main-revisions, r=compiler-errors

tests: Add `RUST_BACKTRACE` and `-Cpanic` revisions to `panic-main.rs` test

This is a regression test for rust-lang/rust#123733 (**P-high** and **regression-from-stable-to-stable**) which was [fixed by accident without a regression test](rust-lang/rust#123733 (comment)).

Edit 2025-06-23:

Closes rust-lang/rust#123733

Author: fmease