ci: remove Erlang versions v26, v27, and v28 to legacy jobs

Author: joeljuca

.github/workflows/legacy.yml

@@ -9,7 +9,7 @@ jobs:
     name: elixir-${{ matrix.elixir }}-otp-${{ matrix.otp }}
     strategy:
       matrix:
-        otp: ["24", "25"]
+        otp: ["24", "25", "26", "27", "28"]
         elixir: ["1.15"]
     services:
       postgres:
@@ -42,7 +42,7 @@ jobs:
     name: elixir-${{ matrix.elixir }}-otp-${{ matrix.otp }}
     strategy:
       matrix:
-        otp: ["24", "25"]
+        otp: ["24", "25", "26", "27", "28"]
         elixir: ["1.14"]
     services:
       postgres: