REFACTOR: have a single std loading call (#9033)

# Description
this PR moves the three individual call to `load_standard_library` in
the "Nushell branches" of `run.rs` into a single one, before the `if`,
in `main.rs`.

# User-Facing Changes
```
$nothing
```

# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- ⚫ `toolkit test`
- ⚫ `toolkit test stdlib`

# After Submitting
```
$nothing
```

src/main.rs

@@ -22,6 +22,7 @@ use nu_cli::gather_parent_env_vars;
 use nu_command::{create_default_context, get_init_cwd};
 use nu_protocol::{report_error_new, Value};
 use nu_protocol::{util::BufferedReader, PipelineData, RawStream};
+use nu_std::load_standard_library;
 use nu_utils::utils::perf;
 use run::{run_commands, run_file, run_repl};
 use signals::{ctrlc_protection, sigquit_protection};
@@ -250,6 +251,10 @@ fn main() -> Result<()> {
         use_color,
     );
 
+    if parsed_nu_cli_args.no_std_lib.is_none() {
+        load_standard_library(&mut engine_state)?;
+    }
+
     if let Some(commands) = parsed_nu_cli_args.commands.clone() {
         run_commands(
             &mut engine_state,

src/run.rs

@@ -8,7 +8,6 @@ use crate::{
 use nu_cli::read_plugin_file;
 use nu_cli::{evaluate_commands, evaluate_file, evaluate_repl};
 use nu_protocol::PipelineData;
-use nu_std::load_standard_library;
 use nu_utils::utils::perf;
 
 pub(crate) fn run_commands(
@@ -22,10 +21,6 @@ pub(crate) fn run_commands(
     let mut stack = nu_protocol::engine::Stack::new();
     let start_time = std::time::Instant::now();
 
-    if parsed_nu_cli_args.no_std_lib.is_none() {
-        load_standard_library(engine_state)?;
-    }
-
     #[cfg(feature = "plugin")]
     read_plugin_file(
         engine_state,
@@ -113,10 +108,6 @@ pub(crate) fn run_file(
     let mut stack = nu_protocol::engine::Stack::new();
     let start_time = std::time::Instant::now();
 
-    if parsed_nu_cli_args.no_std_lib.is_none() {
-        load_standard_library(engine_state)?;
-    }
-
     #[cfg(feature = "plugin")]
     read_plugin_file(
         engine_state,
@@ -214,10 +205,6 @@ pub(crate) fn run_repl(
     let mut stack = nu_protocol::engine::Stack::new();
     let start_time = std::time::Instant::now();
 
-    if parsed_nu_cli_args.no_std_lib.is_none() {
-        load_standard_library(engine_state)?;
-    }
-
     if parsed_nu_cli_args.no_config_file.is_none() {
         setup_config(
             engine_state,