fix: delete conda dir and micromamba.exe if legacy version installed

The change from `micromamba.bat` to `mamba.bat` isn't worth supporting backwards for. Running update-runtime already has the practical effect of reinstalling micromamba's conda venv, so it should be generally seen as safe to remove the directory as its rooted to the script folder and should otherwise be seen as managed by the worker code.

update-runtime.cmd

@@ -1,15 +1,33 @@
 @echo off
+cd /d "%~dp0"
+
+SET MAMBA_ROOT_PREFIX=%~dp0conda
+echo %MAMBA_ROOT_PREFIX%
+
+if exist "%MAMBA_ROOT_PREFIX%\condabin\micromamba.bat" (
+    echo Deleting micromamba.exe as its out of date
+    del micromamba.exe
+    if errorlevel 1 (
+        echo Error: Failed to delete micromamba.exe. Please delete it manually.
+        exit /b 1
+    )
+    echo Deleting the conda directory as its out of date
+    rmdir /s /q conda
+    if errorlevel 1 (
+        echo Error: Failed to delete the conda directory. Please delete it manually.
+        exit /b 1
+    )
+)
+
 :Check if micromamba is already installed
 if exist micromamba.exe goto Isolation
   curl.exe -L -o micromamba.exe https://github.com/mamba-org/micromamba-releases/releases/latest/download/micromamba-win-64
 
-cd /d "%~dp0"
 
 :Isolation
 SET CONDA_SHLVL=
 SET PYTHONNOUSERSITE=1
 SET PYTHONPATH=
-SET MAMBA_ROOT_PREFIX=%~dp0conda
 echo %MAMBA_ROOT_PREFIX%