Add more `begin_panic` normalizations to panic backtrace tests
Since #123244, these tests have started failing locally on some systems (#133997) due to minor variations in how `begin_panic` is printed in the backtrace.
The variation appears to occur on macOS when `rust.debuginfo-level = "line-tables-only"` is set, which is the default in `config.compiler.toml`. It does not occur when the debuginfo level is set to 1.
The variation doesn't seem relevant to these tests, so this PR simply adds another custom normalization rule to account for the variation.
---
Will conflict with #134759.
3d50eba781