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

[LikeLakers2]

Objective

• Warn the clippy::allow_attributes and clippy::allow_attributes_without_reason lints #17111

Solution

Set the clippy::allow_attributes and clippy::allow_attributes_without_reason lints to deny, and bring bevy_time in line with the new restrictions.

No code changes have been made - except if a lint that was previously allow(...)'d could be removed via small code changes. For example, unused_variables can be handled by adding a _ to the beginning of a field's name.

Testing

cargo clippy, cargo clippy --package bevy_time and cargo test --package bevy_time were run, and no errors were encountered.