Better log canonicalization errors (#32030)

Based on
https://github.com/zed-industries/zed/issues/18673#issuecomment-2933025951

Adds an anyhow error context with the path used for canonicalization
(also, explicitly mention path at the place from the comment).

Release Notes:

- N/A

crates/fs/src/fs.rs

@@ -597,7 +597,9 @@ impl Fs for RealFs {
     }
 
     async fn canonicalize(&self, path: &Path) -> Result<PathBuf> {
-        Ok(smol::fs::canonicalize(path).await?)
+        Ok(smol::fs::canonicalize(path)
+            .await
+            .with_context(|| format!("canonicalizing {path:?}"))?)
     }
 
     async fn is_file(&self, path: &Path) -> bool {