debugger: Relax implementation of validate_config to not run validation (#31785)

When we moved to schema-based debug configs, we've added validate_config
- a trait method
that is supposed to both validate the configuration and determine
whether it is a launch configuration
or an attach configuration.

The validation bit is a bit problematic though - we received reports on
Discords about
scenarios not starting up properly; it turned out that Javascript's
implementation was overly strict.
Thus, I got rid of any code that tries to validate the config - let's
let the debug adapter itself
decide whether it can digest the configuration or not. validate_config
is now left unimplemented for most
DebugAdapter implementations (except for PHP), because all adapters use
`request`: 'launch'/'attach' for that.
Let's leave the trait method in place though, as nothing guarantees this
to be true for all adapters.

cc @Anthony-Eid

Release Notes:

- debugger: Improved error messages when the debug scenario is not
valid.
- debugger: Fixed cases where valid configs were rejected.

crates/dap_adapters/src/go.rs

@@ -1,6 +1,6 @@
-use anyhow::{Context as _, anyhow, bail};
+use anyhow::{Context as _, bail};
 use dap::{
-    StartDebuggingRequestArguments, StartDebuggingRequestArgumentsRequest,
+    StartDebuggingRequestArguments,
     adapters::{
         DebugTaskDefinition, DownloadedFileType, download_adapter_from_github,
         latest_github_release,
@@ -350,24 +350,6 @@ impl DebugAdapter for GoDebugAdapter {
         })
     }
 
-    fn validate_config(
-        &self,
-        config: &serde_json::Value,
-    ) -> Result<StartDebuggingRequestArgumentsRequest> {
-        let map = config.as_object().context("Config isn't an object")?;
-
-        let request_variant = map
-            .get("request")
-            .and_then(|val| val.as_str())
-            .context("request argument is not found or invalid")?;
-
-        match request_variant {
-            "launch" => Ok(StartDebuggingRequestArgumentsRequest::Launch),
-            "attach" => Ok(StartDebuggingRequestArgumentsRequest::Attach),
-            _ => Err(anyhow!("request must be either 'launch' or 'attach'")),
-        }
-    }
-
     fn config_from_zed_format(&self, zed_scenario: ZedDebugConfig) -> Result<DebugScenario> {
         let mut args = match &zed_scenario.request {
             dap::DebugRequest::Attach(attach_config) => {
@@ -488,7 +470,7 @@ impl DebugAdapter for GoDebugAdapter {
             connection: None,
             request_args: StartDebuggingRequestArguments {
                 configuration: task_definition.config.clone(),
-                request: self.validate_config(&task_definition.config)?,
+                request: self.request_kind(&task_definition.config)?,
             },
         })
     }