ci: suffix debug-build artifacts to avoid release filename collision

`actions/download-artifact@v8` with `merge-multiple: true` extracts every
artifact into the same Release/ directory in parallel. Release and Debug
builds of the same platform produced identical CPack/AppImage filenames
(isle-0.1-Windows-x64.zip, isle-0.1-Linux-x64.tar.gz,
Isle_Portable-x86_64.AppImage), so the parallel writes raced on the same
path and intermittently produced corrupt archives in the release.

Append `-debug` to CPACK_PACKAGE_FILE_NAME when ISLE_DEBUG is set, and
rename the AppImage in the same case, so each matrix entry contributes a
unique filename to the release.

Fixes #646

.github/workflows/ci.yml

@@ -243,6 +243,14 @@ jobs:
             --output appimage && \
           mv *.AppImage dist/
 
+      - name: Suffix debug AppImage
+        if: ${{ matrix.linux && matrix.debug }}
+        run: |
+          cd build/dist
+          for f in *.AppImage; do
+            mv "$f" "${f%.AppImage}-debug.AppImage"
+          done
+
       - name: Package (3DS)
         if: ${{ matrix.n3ds }}
         run: |

CMakeLists.txt

@@ -1083,6 +1083,9 @@ add_subdirectory(packaging)
 
 set(CPACK_PACKAGE_DIRECTORY "dist")
 set(CPACK_PACKAGE_FILE_NAME "isle-${PROJECT_VERSION}-${ISLE_PACKAGE_NAME}")
+if(ISLE_DEBUG)
+  string(APPEND CPACK_PACKAGE_FILE_NAME "-debug")
+endif()
 if(NINTENDO_3DS)
   find_program(BANNERTOOL bannertool)
   find_program(MAKEROM makerom)