Add --python-platform to uv pip check (#15486)

## Summary

I want this to facilitate some testing for
https://github.com/astral-sh/uv/issues/15035.

crates/uv-cli/src/lib.rs

@@ -2373,6 +2373,27 @@ pub struct PipCheckArgs {
 
     #[arg(long, overrides_with("system"), hide = true)]
     pub no_system: bool,
+
+    /// The Python version against which packages should be checked.
+    ///
+    /// By default, the installed packages are checked against the version of the current
+    /// interpreter.
+    #[arg(long)]
+    pub python_version: Option<PythonVersion>,
+
+    /// The platform for which packages should be checked.
+    ///
+    /// By default, the installed packages are checked against the platform of the current
+    /// interpreter.
+    ///
+    /// Represented as a "target triple", a string that describes the target platform in terms of
+    /// its CPU, vendor, and operating system name, like `x86_64-unknown-linux-gnu` or
+    /// `aarch64-apple-darwin`.
+    ///
+    /// When targeting macOS (Darwin), the default minimum version is `12.0`. Use
+    /// `MACOSX_DEPLOYMENT_TARGET` to specify a different minimum version, e.g., `13.0`.
+    #[arg(long)]
+    pub python_platform: Option<TargetTriple>,
 }
 
 #[derive(Args)]