chore: fix prompt in launch config to test current file (#7791)

Previous launch config no longer works, either related to vs code update
or extension update, but changing prompt input to use
`extension.commandvariable` specific command does the job.

Also fixes segfault issue by changing from `threads` to `forks`.

.vscode/launch.template.json

@@ -49,8 +49,8 @@
         "-t",
         "${input:testName}",
         "--pool",
-        "threads",
-        "--poolOptions.threads.singleThread"
+        "forks",
+        "--poolOptions.forks.singleFork"
       ],
       "cwd": "${workspaceFolder}/${input:packageName}",
       "console": "integratedTerminal",
@@ -72,8 +72,12 @@
     },
     {
       "id": "testName",
-      "type": "promptString",
-      "description": "Enter the test name to run, leave empty to run all"
+      "type": "command",
+      "command": "extension.commandvariable.promptStringRemember",
+      "args": {
+        "key": "testName",
+        "description": "Enter the test name to run, leave empty to run all"
+      }
     }
   ]
 }

docs/pages/contribution/tools/debugging.md

@@ -6,7 +6,7 @@ This page describes different approaches for debugging Lodestar.
 
 The simplest way to debug is to use the provided [launch.template.json](https://github.com/ChainSafe/lodestar/blob/unstable/.vscode/launch.template.json) `configurations`. Copy them as `.vscode/launch.json` and they will be made available in the `Run and Debug` section in VS Code. Adapt as needed, e.g. by adding additional arguments to the beacon [configuration](https://github.com/ChainSafe/lodestar/blob/unstable/.vscode/launch.template.json#L22) to match your needs.
 
-VS Code supports debugging Workers out of the box when using those configurations.
+VS Code supports debugging Workers out of the box when using those configurations. The `Test Current File` launch configuration additionally requires to install [Command Variable](https://marketplace.visualstudio.com/items/?itemName=rioj7.command-variable) extension to correctly parse input prompts.
 
 ## Attach to running process