Github action: Remove unnecessary entries

Author: joto

.github/workflows/ci.yml

@@ -22,37 +22,23 @@ jobs:
           - "fedora:43"
         build_type: [Dev]
         cpp_compiler: [g++]
-        cpp_version: [c++17]
         include:
           - image: "ubuntu:22.04"
             CXXFLAGS: -Wno-stringop-overread -Wno-array-bounds
           - image: "ubuntu:24.04"
             CXXFLAGS: -Wno-stringop-overread -Wno-array-bounds
           - image: "debian:bookworm"
             CXXFLAGS: -Wno-stringop-overread -Wno-array-bounds
-          - image: "debian:bookworm"
-            cpp_version: c++20
           - image: "debian:bookworm"
             c_compiler: clang
             cpp_compiler: clang++
-          - image: "debian:bookworm"
-            c_compiler: clang
-            cpp_compiler: clang++
-            cpp_version: c++20
           - image: "debian:bookworm"
             build_type: RelWithDebInfo
           - image: "debian:trixie"
             CXXFLAGS: -Wno-stringop-overread -Wno-array-bounds
-          - image: "debian:trixie"
-            cpp_version: c++20
-            CXXFLAGS: -Wno-stringop-overread -Wno-array-bounds
-          - image: "debian:trixie"
-            c_compiler: clang
-            cpp_compiler: clang++
           - image: "debian:trixie"
             c_compiler: clang
             cpp_compiler: clang++
-            cpp_version: c++20
           - image: "debian:trixie"
             build_type: RelWithDebInfo
             CXXFLAGS: -Wno-stringop-overread -Wno-array-bounds
@@ -83,7 +69,6 @@ jobs:
         CXX: ${{ matrix.cpp_compiler }}
         CXXFLAGS: ${{ matrix.CXXFLAGS }}
         LDFLAGS: ${{ matrix.LDFLAGS }}
-        CPP_VERSION: ${{ matrix.cpp_version }}
         APT_LISTCHANGES_FRONTEND: none
         DEBIAN_FRONTEND: noninteractive
     steps: