Remove superfluous definition of point_from_cursor()

There's a more robust version already in `crates/ark/src/fixtures/utils.rs`.

Author: jennybc

crates/ark/src/lsp/completions/parameter_hints.rs

@@ -117,20 +117,14 @@ fn skip_namespace_operator(node: Node) -> Node {
 mod tests {
     use tower_lsp::lsp_types::CompletionItem;
     use tower_lsp::lsp_types::InsertTextFormat;
-    use tree_sitter::Point;
 
+    use crate::fixtures::point_from_cursor;
     use crate::lsp::completions::provide_completions;
     use crate::lsp::document_context::DocumentContext;
     use crate::lsp::documents::Document;
     use crate::lsp::state::WorldState;
     use crate::r_task;
 
-    fn point_from_cursor(text: &str) -> (String, Point) {
-        let cursor_pos = text.find('@').unwrap();
-        let text = text.replace('@', "");
-        (text, Point::new(0, cursor_pos))
-    }
-
     fn find_completion(completions: &[CompletionItem], label: &str) -> CompletionItem {
         completions
             .iter()