Remove php-7.x branches

Author: alphp

.github/workflows/build.yml

@@ -18,7 +18,7 @@ jobs:
         strategy:
             fail-fast: false
             matrix:
-                php: ["7.3", "7.4", "8.0", "8.1", "8.2", "8.3", "8.4"]
+                php: ["8.0", "8.1", "8.2", "8.3", "8.4"]
                 arch: [x86, x64]
                 ts: [nts, ts]
                 experimental: [false]