Drop support of Qt 5

Also remove usage of some deprecated stuff.

PR #19338.

.github/workflows/ci_macos.yaml

@@ -19,7 +19,7 @@ jobs:
       matrix:
         libt_version: ["2.0.9", "1.2.19"]
         qbt_gui: ["GUI=ON", "GUI=OFF"]
-        qt_version: ["5.15.2", "6.5.0"]
+        qt_version: ["6.5.0"]
         exclude:
           - libt_version: "1.2.19"
             qt_version: "6.5.0"
@@ -88,25 +88,6 @@ jobs:
           cmake --build build
           sudo cmake --install build
 
-      - name: Build qBittorrent (Qt5)
-        if: startsWith(matrix.qt_version, 5)
-        run: |
-          CXXFLAGS="$CXXFLAGS -Werror -Wno-error=deprecated-declarations" \
-          LDFLAGS="$LDFLAGS -gz" \
-          cmake \
-            -B build \
-            -G "Ninja" \
-            -DCMAKE_BUILD_TYPE=RelWithDebInfo \
-            -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
-            -DBOOST_ROOT="${{ env.boost_path }}" \
-            -DOPENSSL_ROOT_DIR="${{ env.openssl_root }}" \
-            -DTESTING=ON \
-            -DVERBOSE_CONFIGURE=ON \
-            -D${{ matrix.qbt_gui }}
-          cmake --build build --target qbt_update_translations
-          cmake --build build
-          cmake --build build --target check
-
       - name: Build qBittorrent (Qt6)
         if: startsWith(matrix.qt_version, 6)
         run: |
@@ -119,7 +100,6 @@ jobs:
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
             -DBOOST_ROOT="${{ env.boost_path }}" \
             -DOPENSSL_ROOT_DIR="${{ env.openssl_root }}" \
-            -DQT6=ON \
             -DTESTING=ON \
             -DVERBOSE_CONFIGURE=ON \
             -D${{ matrix.qbt_gui }}

.github/workflows/ci_ubuntu.yaml

@@ -20,7 +20,7 @@ jobs:
       matrix:
         libt_version: ["2.0.9", "1.2.19"]
         qbt_gui: ["GUI=ON", "GUI=OFF"]
-        qt_version: ["5.15.2", "6.2.0"]
+        qt_version: ["6.2.0"]
         exclude:
           - libt_version: "1.2.19"
             qt_version: "6.2.0"
@@ -75,25 +75,6 @@ jobs:
           config-file: ./.github/workflows/helper/codeql/cpp.yaml
           languages: cpp
 
-      - name: Build qBittorrent (Qt5)
-        if: startsWith(matrix.qt_version, 5)
-        run: |
-          CXXFLAGS="$CXXFLAGS -Werror -Wno-error=deprecated-declarations" \
-          LDFLAGS="$LDFLAGS -gz" \
-          cmake \
-            -B build \
-            -G "Ninja" \
-            -DCMAKE_BUILD_TYPE=RelWithDebInfo \
-            -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
-            -DCMAKE_INSTALL_PREFIX="/usr" \
-            -DTESTING=ON \
-            -DVERBOSE_CONFIGURE=ON \
-            -D${{ matrix.qbt_gui }}
-          cmake --build build --target qbt_update_translations
-          cmake --build build
-          cmake --build build --target check
-          DESTDIR="qbittorrent" cmake --install build
-
       - name: Build qBittorrent (Qt6)
         if: startsWith(matrix.qt_version, 6)
         run: |
@@ -105,7 +86,6 @@ jobs:
             -DCMAKE_BUILD_TYPE=RelWithDebInfo \
             -DCMAKE_EXPORT_COMPILE_COMMANDS=ON \
             -DCMAKE_INSTALL_PREFIX="/usr" \
-            -DQT6=ON \
             -DTESTING=ON \
             -DVERBOSE_CONFIGURE=ON \
             -D${{ matrix.qbt_gui }}

.github/workflows/ci_windows.yaml

@@ -118,7 +118,6 @@ jobs:
             -DBOOST_ROOT="${{ env.boost_path }}" `
             -DLibtorrentRasterbar_DIR="${{ env.libtorrent_path }}/lib/cmake/LibtorrentRasterbar" `
             -DMSVC_RUNTIME_DYNAMIC=OFF `
-            -DQT6=ON `
             -DTESTING=ON `
             -DVCPKG_TARGET_TRIPLET=x64-windows-static-release `
             -DVERBOSE_CONFIGURE=ON `

.github/workflows/coverity-scan.yaml

@@ -62,7 +62,6 @@ jobs:
             -G "Ninja" \
             -DCMAKE_BUILD_TYPE=RelWithDebInfo \
             -DGUI=ON \
-            -DQT6=ON \
             -DVERBOSE_CONFIGURE=ON
           export PATH="$(pwd)/coverity_tool/bin:$PATH"
           cov-build --dir cov-int cmake --build build