Search for all python3.x in PATH (#5148)

Search for all `python3.x` minor versions in PATH, skipping those we
already know we can use.

For example, let's say `python` and `python3` are Python 3.10. When a
user requests `>= 3.11`, we still need to find a `python3.12` in PATH.
We do so with a regex matcher.

Fixes #4709

crates/uv-python/src/lib.rs

@@ -33,6 +33,7 @@ mod python_version;
 mod target;
 mod version_files;
 mod virtualenv;
+mod which;
 
 #[cfg(not(test))]
 pub(crate) fn current_dir() -> Result<std::path::PathBuf, std::io::Error> {
@@ -1752,6 +1753,32 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn find_python_all_minors() -> Result<()> {
+        let mut context = TestContext::new()?;
+        context.add_python_interpreters(&[
+            (true, ImplementationName::CPython, "python", "3.10.0"),
+            (true, ImplementationName::CPython, "python3", "3.10.0"),
+            (true, ImplementationName::CPython, "python3.12", "3.12.0"),
+        ])?;
+
+        let python = context.run(|| {
+            find_python_installation(
+                &PythonRequest::parse(">= 3.11"),
+                EnvironmentPreference::Any,
+                PythonPreference::OnlySystem,
+                &context.cache,
+            )
+        })??;
+        assert_eq!(
+            python.interpreter().python_full_version().to_string(),
+            "3.12.0",
+            "We should find matching minor version even if they aren't called `python` or `python3`"
+        );
+
+        Ok(())
+    }
+
     #[test]
     fn find_python_pypy_prefers_executable_with_implementation_name() -> Result<()> {
         let mut context = TestContext::new()?;