add clippy warning for string_slice (#5422)

Co-authored-by: Douwe Osinga <douwe@squareup.com>

crates/goose/src/providers/utils.rs

@@ -47,6 +47,31 @@ pub fn convert_image(image: &ImageContent, image_format: &ImageFormat) -> Value
     }
 }
 
+pub fn filter_extensions_from_system_prompt(system: &str) -> String {
+    let Some(extensions_start) = system.find("# Extensions") else {
+        return system.to_string();
+    };
+
+    let Some(after_extensions) = system.get(extensions_start + 1..) else {
+        return system.to_string();
+    };
+
+    if let Some(next_section_pos) = after_extensions.find("\n# ") {
+        let Some(before) = system.get(..extensions_start) else {
+            return system.to_string();
+        };
+        let Some(after) = system.get(extensions_start + next_section_pos + 1..) else {
+            return system.to_string();
+        };
+        format!("{}{}", before.trim_end(), after)
+    } else {
+        system
+            .get(..extensions_start)
+            .map(|s| s.trim_end().to_string())
+            .unwrap_or_else(|| system.to_string())
+    }
+}
+
 fn check_context_length_exceeded(text: &str) -> bool {
     let check_phrases = [
         "too long",