[stable2503] Backport #8198 (#8207)

Backport #8198 into `stable2503` from koute.

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[documentation](https://github.com/paritytech/polkadot-sdk/blob/master/docs/BACKPORT.md)
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Co-authored-by: Koute <[email protected]>
Co-authored-by: cmd[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Egor_P <[email protected]>
Co-authored-by: Oliver Tale-Yazdi <[email protected]>

Author: 5 people

prdoc/pr_8198.prdoc

@@ -0,0 +1,12 @@
+title: Remove `#[no_mangle]` from the panic handler
+doc:
+- audience: Runtime Dev
+  description: |-
+    Fixes https://github.com/paritytech/polkadot-sdk/issues/8190
+
+    Remove useless `#[no_mangle]` from the panic handler which screws up the panic handling machinery on recent versions of Rust.
+crates:
+- name: substrate-wasm-builder
+  bump: patch
+- name: sp-io
+  bump: patch

substrate/primitives/io/src/lib.rs

@@ -1771,7 +1771,6 @@ pub fn unreachable() -> ! {
 /// A default panic handler for the runtime environment.
 #[cfg(all(not(feature = "disable_panic_handler"), substrate_runtime))]
 #[panic_handler]
-#[no_mangle]
 pub fn panic(info: &core::panic::PanicInfo) -> ! {
 	let message = alloc::format!("{}", info);
 	#[cfg(feature = "improved_panic_error_reporting")]