Replace git current_branch to shadow-rs branch (#2935)

* update to shadow-rs 0.4. use easy

* update shadow-rs to 0.5

* fix version not used

* update

* update Cargo.lock

* update Cargo.lock

* fix wasm build error when use dependence git2
fix error link:https://dev.azure.com/nushell/nushell/_build/results?buildId=4858&view=logs&j=1a745d4c-b027-5f34-06d8-d6f256bfe9f9&t=a0a335cb-fa1f-5bbf-be01-1a90d6899e54

* remove code not used; fix warning by RUSTFLAGS="-D warnings" build error

* upgrade shadow-rs 0.5.2

* upgrade shadow-rs 0.5.7

make nushell reduce dependence crates smaller and  build fast.

* upgrade shadow-rs 0.5.8

fix when use api 'strip_prefix()' method in less than rust1.45.0 build failed

* use shadow-rs branch replace with current_branch method;
remove and reduce git dependencies.

* upgrade shadow-rs 0.5.12-pre,test build error with wasm

* upgrade Cargo.lock

* upgarde shadow-rs depencdence

* fix build error in wasm

* add clippy warning

crates/nu-command/src/commands/version.rs

@@ -165,11 +165,6 @@ fn features_enabled() -> Vec<String> {
         names.push("directories".to_string());
     }
 
-    #[cfg(feature = "git2")]
-    {
-        names.push("git".to_string());
-    }
-
     #[cfg(feature = "ptree")]
     {
         names.push("ptree".to_string());