Add SCons install to CI build scripts

.github/workflows/build.yml

@@ -9,14 +9,17 @@ jobs:
       - uses: actions/checkout@v2
       - name: Debug Ubuntu
         run: |
+          pip3 install --user scons
           . ./build_libs.sh Debug
           scons platform=x11 target=debug
+
   build-release-ubuntu:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
       - name: Release Ubuntu
         run: |
+          pip3 install --user scons
           . ./build_libs.sh Release
           scons platform=x11 target=release
 
@@ -24,16 +27,27 @@ jobs:
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+          architecture: 'x64'
       - name: Debug Windows
         run: |
+          pip3 install --user scons
           ./build_libs.bat Debug
           scons platform=windows target=debug
+
   build-release-windows:
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+          architecture: 'x64'
       - name: Release Windows
         run: |
+          pip3 install --user scons
           ./build_libs.bat Release
           scons platform=windows target=release
 
@@ -43,13 +57,16 @@ jobs:
       - uses: actions/checkout@v2
       - name: Debug macOS
         run: |
+          brew install scons
           . ./build_libs_mac.sh Debug
           scons platform=osx target=debug
+
   build-release-macos:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v2
       - name: Release macOS
         run: |
+          brew install scons
           . ./build_libs_mac.sh Release
           scons platform=osx target=release

build_libs.bat

@@ -13,12 +13,10 @@ copy godot-git-plugin\thirdparty\libgit2\build\%1\git2.lib demo\bin\win64\
 
 if "%CI%"=="" (
     echo Non-CI build detected
-    set SCONS=scons
 ) else (
     echo CI build detected
-    set SCONS=..\scons.bat
 )
 
 cd godot-cpp\
-%SCONS% platform=windows target=%1 generate_bindings=yes bits=64
+scons platform=windows target=%1 generate_bindings=yes bits=64
 cd ..