Improve GitHub Actions test matrix for Elixir/OTP

Test on newer Elixir and OTP, limit old Elixir versions to a single OTP
version.

Author: lucaong

.github/workflows/elixir.yml

@@ -80,39 +80,26 @@ jobs:
     runs-on: ubuntu-20.04 # Later Ubuntu versions do not have OTP 22
     strategy:
       matrix:
-        otp: ['22.3', '23.3', '24.3', '25.2']
-        elixir: ['1.7.4', '1.8.2', '1.9.4', '1.10.4', '1.11.4', '1.12.3', '1.13.4', '1.14.2']
-        exclude:
+        otp: ['25.3', '26.2', '27.1']
+        elixir: ['1.15.8', '1.16.3', '1.17.3']
+        include:
           - otp: '22.3'
-            elixir: '1.14.2'
-          - otp: '23.3'
             elixir: '1.7.4'
-          - otp: '23.3'
+          - otp: '22.3'
             elixir: '1.8.2'
-          - otp: '23.3'
+          - otp: '22.3'
             elixir: '1.9.4'
-          - otp: '23.3'
+          - otp: '22.3'
             elixir: '1.10.4'
           - otp: '24.3'
-            elixir: '1.7.4'
-          - otp: '24.3'
-            elixir: '1.8.2'
-          - otp: '24.3'
-            elixir: '1.9.4'
-          - otp: '24.3'
-            elixir: '1.10.4'
-          - otp: '25.2'
-            elixir: '1.7.4'
-          - otp: '25.2'
-            elixir: '1.8.2'
-          - otp: '25.2'
-            elixir: '1.9.4'
-          - otp: '25.2'
-            elixir: '1.10.4'
-          - otp: '25.2'
             elixir: '1.11.4'
-          - otp: '25.2'
+          - otp: '24.3'
             elixir: '1.12.3'
+          - otp: '25.3'
+            elixir: '1.13.4'
+          - otp: '25.3'
+            elixir: '1.14.5'
+
     steps:
     - uses: actions/checkout@v2
     - name: Set up Elixir