Rollup merge of #132182 - jieyouxu:downgrade-untranslatable, r=compiler-errors

Downgrade `untranslatable_diagnostic` and `diagnostic_outside_of_impl` to `allow`

Current implementation of translatable diagnostics infrastructure unfortunately causes some friction for compiler contributors. While we don't have a redesign that causes less friction in place, let's downgrade the internal `untranslatable_diagnostic` and `diagnostic_outside_of_impl` lints so we don't indicate to contributors that they *have* to use the current translation infra.

I purposefully left `#[allow(untranslatable_diagnostic)]` and `#[allow(diagnostic_outside_of_impl)]` instances untouched because that seems like unnecessary additional churn.

See <#132181> for context.

r? `@davidtwco` (or wg-diagnostics/compiler)

Author: matthiaskrgr

Diff for: compiler/rustc_lint/src/internal.rs

@@ -427,7 +427,7 @@ declare_tool_lint! {
     /// More details on translatable diagnostics can be found
     /// [here](https://rustc-dev-guide.rust-lang.org/diagnostics/translation.html).
     pub rustc::UNTRANSLATABLE_DIAGNOSTIC,
-    Deny,
+    Allow,
     "prevent creation of diagnostics which cannot be translated",
     report_in_external_macro: true
 }
@@ -440,7 +440,7 @@ declare_tool_lint! {
     /// More details on diagnostics implementations can be found
     /// [here](https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html).
     pub rustc::DIAGNOSTIC_OUTSIDE_OF_IMPL,
-    Deny,
+    Allow,
     "prevent diagnostic creation outside of `Diagnostic`/`Subdiagnostic`/`LintDiagnostic` impls",
     report_in_external_macro: true
 }