vim: Fix clipping when navigating over inlay hints (#22813)

This fixes the issue described in this comment:
https://github.com/zed-industries/zed/pull/22439#issuecomment-2563896422

Essentially, we'd clip in the wrong direction when there were multi-line
inlay hints.

It also fixes inline completions for non-Zeta-providers showing up in
normal mode.

Release Notes:

- N/A

crates/copilot/src/copilot_completion_provider.rs

@@ -63,6 +63,10 @@ impl InlineCompletionProvider for CopilotCompletionProvider {
         false
     }
 
+    fn show_completions_in_normal_mode() -> bool {
+        false
+    }
+
     fn is_enabled(
         &self,
         buffer: &Model<Buffer>,