linux_and_macos.yml: Drop compilation with Clang 17

.. because Clang 18 is stricter, we have no Code specific to Clang 17,
and bmake on Linux is still covered by other matrix entries.

Author: hartwork

.github/workflows/linux_and_macos.yml

@@ -28,12 +28,6 @@ jobs:
             clang_repo_suffix: null
             make: make
             runs-on: ubuntu-22.04
-          - cc: clang-17
-            cxx: clang++-17
-            clang_major_version: 17
-            clang_repo_suffix: -17
-            make: bmake
-            runs-on: ubuntu-22.04
           - cc: clang-18
             cxx: clang++-18
             clang_major_version: 18