ci: no need to do a final cd

.github/workflows/build.yml

@@ -32,8 +32,7 @@ jobs:
         C:\msys64\usr\bin\wget.exe https://archive.org/download/idx5sdk/idx5sdk.exe
         7z x .\idx5sdk.exe
         7z x .\DX5SDK.EXE
-        cd cdrom
-        
+
     - name: Cache DX5 SDK
       if: steps.cache-dx5.outputs.cache-hit != 'true'
       id: save-dx5
@@ -41,20 +40,20 @@ jobs:
       with:
         path: dx5sdk
         key: dx5sdk
-        
+
     - name: Setup DX5 SDK
       run: |
         cd dx5sdk
         cd cdrom
         .\SETUP.EXE /s
-        
+
     - name: Build
       shell: cmd
       run: |
         call .\msvc420\bin\VCVARS32.BAT x86
         mkdir Release
         .\msvc420\bin\NMAKE.EXE /f isle.mak CFG="ISLE - Win32 Release"
-      
+
     - name: Upload Artifact
       uses: actions/upload-artifact@master
       with: