fix(html_formatter): use method call for separator access

Changed separator access from field reference (&element.trailing_separator)
to method call (element.trailing_separator()) for consistency with other
formatters throughout the codebase.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: wagenet

crates/biome_html_formatter/src/js/lists/path_segment_list.rs

@@ -9,7 +9,7 @@ impl FormatRule<GlimmerPathSegmentList> for FormatGlimmerPathSegmentList {
         // For separated lists, format each element and its separator
         for element in node.elements() {
             crate::prelude::write!(f, [element.node.format()])?;
-            if let Ok(Some(sep)) = &element.trailing_separator {
+            if let Ok(Some(sep)) = element.trailing_separator() {
                 crate::prelude::write!(f, [sep.format()])?;
             }
         }