Make `extension` key context case-insensitive (#45961)

Krzysztof Furman created

Closes #45960 

Release Notes:

- Made the `extension` key context case-insensitive. This e.g. enables
the `markdown: Open Preview` action to also handle files where the
extension is capitalised as MD (case-sensitive file system).

Change summary

crates/editor/src/editor.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Detailed changes

crates/editor/src/editor.rs 🔗

@@ -2680,7 +2680,7 @@ impl Editor {
                     file.full_path(cx)
                         .extension()?
                         .to_string_lossy()
-                        .into_owned(),
+                        .to_lowercase(),
                 )
             }) {
                 key_context.set("extension", extension);