DAP - Terminate Request is not sent for "Attach" Configurations

### Details <!-- ⚠️⚠️ Do Not Delete This! bug_report_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- 🕮 Read our guide about submitting issues: https://github.com/microsoft/vscode/wiki/Submitting-Bugs-and-Suggestions --> <!-- 🔎 Search existing issues to avoid creating duplicates. --> <!-- 🧪 Test using the latest Insiders build to see if your issue has already been fixed: https://code.visualstudio.com/insiders/ --> <!-- 💡 Instead of creating your report here, use 'Report Issue' from the 'Help' menu in VS Code to pre-fill useful information. --> <!-- 🔧 Launch with `code --disable-extensions` to check. --> **Does this issue occur when all extensions are disabled?:** N/A <!-- 🪓 If you answered No above, use 'Help: Start Extension Bisect' from Command Palette to try to identify the cause. --> <!-- 📣 Issues caused by an extension need to be reported directly to the extension publisher. The 'Help > Report Issue' dialog can assist with this. --> - **VS Code Version:** 1.64.2 - **OS Version:** macOS 12.2.1 ### Steps to Reproduce 1. Initialize a Debug Session with `supportsTerminateRequest`. 2. Create an "attach" configuration. 3. Start a debug session using the "attach" configuration. 4. Press Alt/Option to show the "Stop" button in the Debugger UI. 5. Click the "Stop" button. ### Expectation If I implement a Debug Adapter that supports the Terminate Request so that I can handle the two-phase "Graceful Termination", then I expect that functionality to work in both "Launch" and "Attach" configurations. If the user presses the "Stop" button, then this internally indicates "terminate debuggee". This is indicated by the fact that the `terminateDebuggee` Disconnect Request argument is `true` (if support is enabled) when the user presses the "Stop" button. This applies to both "Attach" and "Launch" configurations. ### Reality The Terminate Request is never called for Debug Sessions started with "Attach" config…