Use jom for Windows CI builds

.appveyor.yml

@@ -8,6 +8,7 @@ image:
 
 environment:
   NSISDIR: C:\Program Files (x86)\NSIS
+  JOMDIR: C:\Qt\Tools\QtCreator\bin\jom
   matrix:
   - QTDIR: C:\Qt\5.15\msvc2019_64
     OPENSSLDIR: C:\OpenSSL-v111-Win64\bin
@@ -17,14 +18,14 @@ environment:
 
 install:
 - cmd: |-
-    set PATH=%QTDIR%\bin;%NSISDIR%;%PATH%
+    set PATH=%QTDIR%\bin;%NSISDIR%;%JOMDIR%;%PATH%
     call "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvars64.bat
 
 build_script:
 - cmd: |-
     lrelease gpxsee.pro
     qmake gpxsee.pro
-    nmake release
+    jom release
 
     md installer
     copy release\GPXSee.exe installer

.github/workflows/android.yml

@@ -43,7 +43,7 @@ jobs:
       - name: Configure build
         run:  qmake gpxsee.pro OPENSSL_PATH=android_openssl 
       - name: Build project
-        run:  make -j2 apk
+        run:  make -j4 apk
       - name: Upload artifacts
         uses: actions/upload-artifact@v4
         with:

.github/workflows/linux.yml

@@ -24,4 +24,4 @@ jobs:
       - name: Configure build
         run: qmake CONFIG+=${{ matrix.config }} gpxsee.pro
       - name: Build project
-        run: make -j2
+        run: make -j4