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/python.rs

@@ -1,9 +1,6 @@
 use crate::*;
-use anyhow::{Context as _, anyhow};
-use dap::{
-    DebugRequest, StartDebuggingRequestArguments, StartDebuggingRequestArgumentsRequest,
-    adapters::DebugTaskDefinition,
-};
+use anyhow::Context as _;
+use dap::{DebugRequest, StartDebuggingRequestArguments, adapters::DebugTaskDefinition};
 use gpui::{AsyncApp, SharedString};
 use json_dotpath::DotPaths;
 use language::{LanguageName, Toolchain};
@@ -86,7 +83,7 @@ impl PythonDebugAdapter {
         &self,
         task_definition: &DebugTaskDefinition,
     ) -> Result<StartDebuggingRequestArguments> {
-        let request = self.validate_config(&task_definition.config)?;
+        let request = self.request_kind(&task_definition.config)?;
 
         let mut configuration = task_definition.config.clone();
         if let Ok(console) = configuration.dot_get_mut("console") {
@@ -254,24 +251,6 @@ impl DebugAdapter for PythonDebugAdapter {
         })
     }
 
-    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 is not valid")?;
-
-        match request_variant {
-            "launch" => Ok(StartDebuggingRequestArgumentsRequest::Launch),
-            "attach" => Ok(StartDebuggingRequestArgumentsRequest::Attach),
-            _ => Err(anyhow!("request must be either 'launch' or 'attach'")),
-        }
-    }
-
     async fn dap_schema(&self) -> serde_json::Value {
         json!({
             "properties": {