Remove homebrew-based CI

It fixes #41 
As done in robotology/robotology-superbuild#1407 and several other robotology repositories, we keep macOs CI only conda-based

Author: Nicogene

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
     strategy:
       matrix:
         build_type: [Release]
-        os: [windows-latest, ubuntu-latest, macOS-latest]
+        os: [windows-latest, ubuntu-latest]
 
     steps:
     - uses: actions/checkout@main
@@ -67,10 +67,6 @@ jobs:
                             qtbase5-dev qtdeclarative5-dev qtmultimedia5-dev libtinyxml-dev libgsl-dev wget curl autoconf \
                             autogen automake libtool mlocate libopencv-dev
 
-    - name: Dependencies [macOS]
-      if: matrix.os == 'macOS-latest'
-      run: |
-        brew install ace cmake eigen gsl ipopt opencv pkg-config qt5
     - name: Source-based Dependencies [Windows] 
       if: matrix.os == 'windows-latest'
       shell: bash
@@ -107,8 +103,8 @@ jobs:
                      -DCMAKE_PREFIX_PATH=${GITHUB_WORKSPACE}/install -DCMAKE_INSTALL_PREFIX=${GITHUB_WORKSPACE}/install -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} ..        
         cmake --build . --config ${{ matrix.build_type }} --target INSTALL
         
-    - name: Source-based Dependencies [Ubuntu/macOS]
-      if: matrix.os == 'ubuntu-latest' || matrix.os == 'macOS-latest'
+    - name: Source-based Dependencies [Ubuntu]
+      if: matrix.os == 'ubuntu-latest'
       shell: bash
       run: |
         # ycm
@@ -152,8 +148,8 @@ jobs:
                      -DCMAKE_PREFIX_PATH=${GITHUB_WORKSPACE}/install -DCMAKE_INSTALL_PREFIX=${GITHUB_WORKSPACE}/install \
                      -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} ..
 
-    - name: Configure [Ubuntu/macOS]
-      if: matrix.os == 'ubuntu-latest' || matrix.os == 'macOS-latest'
+    - name: Configure [Ubuntu]
+      if: matrix.os == 'ubuntu-latest'
       shell: bash
       run: |
         mkdir -p build