extensions: Yet another PR for debugger touchups (#32822)

We'll now clean up DAP locators for unloaded extensions and load schemas
proper

I can now load a custom Ruby extensions with all bells and whistles and
use it as my debugger.

Release Notes:

- N/A

crates/debug_adapter_extension/src/extension_dap_adapter.rs

@@ -26,11 +26,13 @@ impl ExtensionDapAdapter {
     pub(crate) fn new(
         extension: Arc<dyn extension::Extension>,
         debug_adapter_name: Arc<str>,
+        schema_path: &Path,
     ) -> Result<Self> {
-        let schema = std::fs::read_to_string(extension.path_from_extension(
-            &Path::new("debug_adapter_schemas").join(debug_adapter_name.as_ref()),
-        ))
-        .with_context(|| format!("Failed to read debug adapter schema for {debug_adapter_name}"))?;
+        let schema = std::fs::read_to_string(&schema_path).with_context(|| {
+            format!(
+                "Failed to read debug adapter schema for {debug_adapter_name} (from path: `{schema_path:?}`)"
+            )
+        })?;
         let schema = serde_json::Value::from_str(&schema).with_context(|| {
             format!("Debug adapter schema for {debug_adapter_name} is not a valid JSON")
         })?;