Revert support of PHP 7.4

Author: ezimuel

.buildkite/pipeline.yml

@@ -16,5 +16,6 @@ steps:
           - "8.2-cli"
           - "8.1-cli"
           - "8.0-cli"
+          - "7.4-cli"
     command: ./.buildkite/run-tests
     artifact_paths: "*.xml"

composer.json

@@ -10,7 +10,7 @@
   "type": "library",
   "license": "MIT",
   "require": {
-    "php": "^8.0",
+    "php": "^7.4 || ^8.0",
     "elastic/transport": "^8.8",
     "psr/http-client": "^1.0",
     "psr/http-message": "^1.1 || ^2.0",