bevy_diagnostic: Apply #![deny(clippy::allow_attributes, clippy::allow_attributes_without_reason)] (#17186)

# Objective
- https://github.com/bevyengine/bevy/issues/17111

## Solution
Set the `clippy::allow_attributes` and
`clippy::allow_attributes_without_reason` lints to `deny`, and bring
`bevy_diagnostic` in line with the new restrictions.

## Testing
`cargo clippy` and `cargo test --package bevy_diagnostic` were run, and
no errors were encountered.

crates/bevy_diagnostic/src/lib.rs

@@ -1,6 +1,11 @@
 #![expect(missing_docs, reason = "Not all docs are written yet, see #3492.")]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![forbid(unsafe_code)]
+#![deny(
+    clippy::allow_attributes,
+    clippy::allow_attributes_without_reason,
+    reason = "See #17111; To be removed once all crates are in-line with these attributes"
+)]
 #![doc(
     html_logo_url = "https://bevyengine.org/assets/icon.png",
     html_favicon_url = "https://bevyengine.org/assets/icon.png"