debugger beta: Fix dap_schema for DAP extensions (#31173)

We now actually call dap_schema provided by extensions instead of
defaulting to a null `serde_json::Value`. We still need to update the
Json LSP whenever a new dap is installed.

Release Notes:

- N/A

crates/dap_adapters/src/codelldb.rs

@@ -175,7 +175,7 @@ impl DebugAdapter for CodeLldbDebugAdapter {
         })
     }
 
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "properties": {
                 "request": {

crates/dap_adapters/src/gdb.rs

@@ -61,7 +61,7 @@ impl DebugAdapter for GdbDebugAdapter {
         })
     }
 
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "oneOf": [
                 {

crates/dap_adapters/src/go.rs

@@ -27,7 +27,7 @@ impl DebugAdapter for GoDebugAdapter {
         Some(SharedString::new_static("Go").into())
     }
 
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         // Create common properties shared between launch and attach
         let common_properties = json!({
             "debugAdapter": {

crates/dap_adapters/src/javascript.rs

@@ -170,7 +170,7 @@ impl DebugAdapter for JsDebugAdapter {
         })
     }
 
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "oneOf": [
                 {

crates/dap_adapters/src/php.rs

@@ -101,7 +101,7 @@ impl PhpDebugAdapter {
 
 #[async_trait(?Send)]
 impl DebugAdapter for PhpDebugAdapter {
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "properties": {
                 "request": {

crates/dap_adapters/src/python.rs

@@ -210,7 +210,7 @@ impl DebugAdapter for PythonDebugAdapter {
         }
     }
 
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "properties": {
                 "request": {

crates/dap_adapters/src/ruby.rs

@@ -31,7 +31,7 @@ impl DebugAdapter for RubyDebugAdapter {
         Some(SharedString::new_static("Ruby").into())
     }
 
-    fn dap_schema(&self) -> serde_json::Value {
+    async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "oneOf": [
                 {