better Caddy install and detection

Author: dunglas

.github/actions/setup-caddy/action.yml

@@ -4,10 +4,5 @@ runs:
   steps:
     - shell: bash
       run: |
-        sudo apt-get install -y debian-keyring debian-archive-keyring apt-transport-https
-        curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | sudo gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
-        curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' | sudo tee /etc/apt/sources.list.d/caddy-stable.list
-        sudo apt-get update
-        sudo apt-get install -y caddy
-
+        sudo curl 'https://caddyserver.com/api/download?os=linux&arch=amd64' > /usr/bin/caddy
         sudo caddy start --config ext/curl/tests/Caddyfile

ext/curl/tests/bug76675.phpt

@@ -4,11 +4,7 @@ Bug #76675 (Segfault with H2 server push write/writeheader handlers)
 curl
 --SKIPIF--
 <?php
-$curl = curl_init();
-curl_setopt($curl, CURLOPT_URL, "https://localhost/serverpush");
-$data = curl_exec($curl);
-curl_close($curl);
-if (!$data) {
+if (!fsockopen("localhost", 443, $errno, $errstr, 0.5)) {
     die("skip test needing Caddy");
 }
 $curl_version = curl_version();

ext/curl/tests/bug77535.phpt

@@ -4,7 +4,7 @@ Bug #77535 (Invalid callback, h2 server push)
 curl
 --SKIPIF--
 <?php
-if (!getenv("RUN_CADDY_TESTS")) {
+if (!fsockopen("localhost", 443, $errno, $errstr, 0.5)) {
     die("skip test needing Caddy");
 }
 $curl_version = curl_version();

ext/curl/tests/curl_pushfunction.phpt

@@ -4,7 +4,7 @@ Test CURLMOPT_PUSHFUNCTION
 curl
 --SKIPIF--
 <?php
-if (!getenv("RUN_CADDY_TESTS")) {
+if (!fsockopen("localhost", 443, $errno, $errstr, 0.5)) {
     die("skip test needing Caddy");
 }
 $curl_version = curl_version();