reset mac support in workflows

reset c85d401662f75d3e8c716daa4a5575b6e23891fd

"chance of revert is 75%"

.github/workflows/why2-project.yml

@@ -11,18 +11,13 @@ jobs:
 
     strategy:
       matrix:
-        os:  [ ubuntu-latest, macos-latest ]
+        os:  [ ubuntu-latest ]
         include:
           - os: ubuntu-latest
             configure: configure.sh
             build: build.sh
             test: test
 
-          - os: macos-latest
-            configure: configure.sh
-            build: build.sh
-            test: test
-
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2

.github/workflows/why2-test.yml

@@ -11,7 +11,7 @@ jobs:
 
     strategy:
       matrix:
-        os:  [ ubuntu-latest, macos-latest ]
+        os:  [ ubuntu-latest ]
         include:
           - os: ubuntu-latest
             output: out/why2-test
@@ -19,12 +19,6 @@ jobs:
             build: build.sh
             app: why2
 
-          - os: macos-latest
-            output: out/why2-test
-            configure: configure.sh
-            build: build.sh
-            app: why2
-
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2
@@ -65,18 +59,13 @@ jobs:
 
     strategy:
       matrix:
-        os:  [ ubuntu-latest, macos-latest ]
+        os:  [ ubuntu-latest ]
         include:
           - os: ubuntu-latest
             output: out/why2-test
             configure: configure.sh
             app: why2
 
-          - os: macos-latest
-            output: out/why2-test
-            configure: configure.sh
-            app: why2
-
     steps:
       - name: Checkout repository
         uses: actions/checkout@v2