Remove Clang-14 support (#394)

Author: Twon

.conan/profiles/clang/14/compiler

@@ -57,20 +57,6 @@ jobs:
               compiler: { type: GCC, version: 15, conan: "gcc", cc: "gcc-15", cxx: "g++-15", std: 23 },
               lib: "libstdc++11"
             }
-          - {
-              name: "Ubuntu Clang-14 + libc++",
-              os: ubuntu-22.04,
-              compiler:
-                {
-                  type: CLANG,
-                  version: 14,
-                  conan: "clang",
-                  cc: "clang-14",
-                  cxx: "clang++-14",
-                  std: 20
-                },
-              lib: "libc++",
-            }
           - {
               name: "Ubuntu Clang-15 + libc++",
               os: ubuntu-22.04,