Ensure PowerShell is available to everyone working on EmuHawk

see #3013
`dotnet tool restore` to install then `dotnet tool run pwsh` or simply
`dotnet pwsh` to launch

.config/dotnet-tools.json

@@ -0,0 +1,13 @@
+{
+  "version": 1,
+  "isRoot": true,
+  "tools": {
+    "powershell": {
+      "version": "7.4.2",
+      "commands": [
+        "pwsh"
+      ],
+      "rollForward": false
+    }
+  }
+}