Rework for new clippy lints (#12736)

- **Clippy lint `assigning_clones`**
- **Clippy lint `legacy_numeric_constants`**
- **`clippy::float_equality_without_abs`**
- **`nu-table`: clippy::zero_repeat_side_effects**

---------

Co-authored-by: Ian Manske <ian.manske@pm.me>

crates/nu-protocol/src/plugin/registry_file/mod.rs

@@ -66,7 +66,7 @@ impl PluginRegistryFile {
         error_span: Option<Span>,
     ) -> Result<(), ShellError> {
         // Update the Nushell version before writing
-        self.nushell_version = env!("CARGO_PKG_VERSION").to_owned();
+        env!("CARGO_PKG_VERSION").clone_into(&mut self.nushell_version);
 
         // Format is brotli compressed messagepack
         let mut brotli_writer =