Fix zlib linkage

.github/workflows/linux.yml

@@ -111,16 +111,6 @@ jobs:
 
           cmake --version
 
-      - name: Zlib.
-        run: |
-          cd $LibrariesPath
-
-          git clone $GIT/madler/zlib.git
-          cd zlib
-          ./configure
-          make -j$(nproc)
-          sudo make install
-
       - name: Opus cache.
         id: cache-opus
         uses: actions/cache@v1

docs/building-cmake.md

@@ -58,13 +58,6 @@ Go to ***BuildPath*** and run
     cd ../
     git clone --branch 0.10.0 https://github.com/ericniebler/range-v3
 
-    git clone https://github.com/madler/zlib.git
-    cd zlib
-    ./configure
-    make $MAKE_THREADS_CNT
-    sudo make install
-    cd ..
-
     git clone https://github.com/xiph/opus
     cd opus
     git checkout v1.3
@@ -254,12 +247,12 @@ Go to ***BuildPath*** and run
     -force-debug-info \
     -opensource \
     -confirm-license \
+    -qt-zlib \
     -qt-libpng \
     -qt-libjpeg \
     -qt-harfbuzz \
     -qt-pcre \
     -qt-xcb \
-    -system-zlib \
     -system-freetype \
     -fontconfig \
     -no-opengl \