Revert "Upgrade to Rust 1.83 (#9511)" (#9617)

This reverts commit cf20673197 (#9511) due
to failure on powerpc64le in https://github.com/astral-sh/uv/pull/9612

crates/uv-python/src/discovery.rs

@@ -1165,17 +1165,17 @@ pub(crate) fn is_windows_store_shim(path: &Path) -> bool {
     }
 
     // Ex) `WindowsApps`
-    if components
+    if !components
         .next()
-        .is_none_or(|component| component.as_os_str() != "WindowsApps")
+        .is_some_and(|component| component.as_os_str() == "WindowsApps")
     {
         return false;
     }
 
     // Ex) `Microsoft`
-    if components
+    if !components
         .next()
-        .is_none_or(|component| component.as_os_str() != "Microsoft")
+        .is_some_and(|component| component.as_os_str() == "Microsoft")
     {
         return false;
     }

crates/uv-python/src/installation.rs

@@ -89,7 +89,7 @@ impl PythonInstallation {
         python_install_mirror: Option<&str>,
         pypy_install_mirror: Option<&str>,
     ) -> Result<Self, Error> {
-        let request = request.unwrap_or(&PythonRequest::Default);
+        let request = request.unwrap_or_else(|| &PythonRequest::Default);
 
         // Search for the installation
         match Self::find(request, environments, preference, cache) {