Fix comment typos and improve wording (#17166)

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## Summary

improve code comments clarity

<!-- What's the purpose of the change? What does it do, and why? -->

## Test Plan

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Signed-off-by: stringscut <stringscut@outlook.jp>

crates/uv-build-frontend/src/lib.rs

@@ -676,7 +676,7 @@ impl SourceBuild {
 
                 // If no `pyproject.toml` is present, by default, proceed with a PEP 517 build using
                 // the default backend, to match `build`. `pip` uses `setup.py` directly in this
-                // case,  but plans to make PEP 517 builds the default in the future.
+                // case, but plans to make PEP 517 builds the default in the future.
                 // See: https://github.com/pypa/pip/issues/9175.
                 Ok((DEFAULT_BACKEND.clone(), None))
             }

crates/uv-client/src/base_client.rs

@@ -1389,7 +1389,7 @@ mod tests {
         let middleware_client = ClientWithMiddleware::default();
         let mut retried = Vec::new();
         for status in 100..599 {
-            // Test all standard status codes and and example for a non-RFC code used in the wild.
+            // Test all standard status codes and an example for a non-RFC code used in the wild.
             if StatusCode::from_u16(status)?.canonical_reason().is_none() && status != 420 {
                 continue;
             }

crates/uv-shell/src/shlex.rs

@@ -18,13 +18,13 @@ pub fn shlex_posix(executable: impl AsRef<Path>) -> String {
 
 /// Escape a string for being used in single quotes in a POSIX-compatible shell command.
 ///
-/// We want our scripts to support any POSIX shell. There's two kind of quotes in POSIX:
+/// We want our scripts to support any POSIX shell. There are two kinds of quotes in POSIX:
 /// Single and double quotes. In bash, single quotes must not contain another single
 /// quote, you can't even escape it (<https://linux.die.net/man/1/bash> under "QUOTING").
-/// Double quotes have escaping rules different from shell to shell, which we can't do.
+/// Double quotes have escaping rules that differ from shell to shell, which we can't handle.
 /// Bash has `$'\''`, but that's not universal enough.
 ///
-/// As solution, use implicit string concatenations, by putting the single quote into double
+/// As a solution, use implicit string concatenations, by putting the single quote into double
 /// quotes.
 pub fn escape_posix_for_single_quotes(string: &str) -> String {
     string.replace('\'', r#"'"'"'"#)

crates/uv/tests/it/init.rs

@@ -2600,7 +2600,7 @@ fn init_existing_environment() -> Result<()> {
     Ok(())
 }
 
-/// Run `uv init`, it should ignore a the Python version from a parent `.venv`
+/// Run `uv init`, it should ignore the Python version from a parent `.venv`
 #[test]
 fn init_existing_environment_parent() -> Result<()> {
     let context = TestContext::new_with_versions(&["3.9", "3.12"]);