Remove unsupported Elixir+OTP pair from CI matrix

Author: tompave

.github/workflows/test.yml

@@ -24,6 +24,12 @@ jobs:
           - '26.2'
           - '25.3'
         exclude:
+          # Elixir 1.18 + OTP 25 is technically supported:
+          #    https://hexdocs.pm/elixir/1.18.1/compatibility-and-deprecations.html#between-elixir-and-erlang-otp
+          # but not on GHA:
+          #    https://github.com/tompave/fun_with_flags/actions/runs/12515433561/job/34912997388?pr=189#step:5:20
+          - elixir: '1.18'
+            otp: '25.3'
           - elixir: '1.16'
             otp: '27.2'
           - elixir: '1.16'