CI: determine actual LibreSSL version dynamically

this change introduce "LIBRESSL_VERSION=latest" semantic, which scans
http://ftp.openbsd.org/pub/OpenBSD/LibreSSL/ and detects latest release.

LIBRESSL_VERSION=2.9.2 is removed from the matrix.

(cherry picked from commit 94cd779a4f3f20d5bb10566994c9f55d07e646b7)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 2b33cf5495eb3dfca1be8c859721bf8759f1e6d8)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/.github/matrix.py b/.github/matrix.py
index 8e7130f..5e56838 100644
--- a/.github/matrix.py
+++ b/.github/matrix.py
@@ -8,6 +8,8 @@
 
 import json
 import sys
+import urllib.request
+import re
 
 if len(sys.argv) == 2:
     build_type = sys.argv[1]
@@ -29,6 +31,13 @@
 def clean_ssl(ssl):
     return ssl.replace("_VERSION", "").lower()
 
+def determine_latest_libressl(ssl):
+    libressl_download_list = urllib.request.urlopen("http://ftp.openbsd.org/pub/OpenBSD/LibreSSL/")
+    for line in libressl_download_list.readlines():
+        decoded_line = line.decode("utf-8")
+        if "libressl-" in decoded_line and ".tar.gz.asc" in decoded_line:
+             l = re.split("libressl-|.tar.gz.asc", decoded_line)[1]
+    return "LIBRESSL={}".format(l)
 
 def clean_compression(compression):
     return compression.replace("USE_", "").lower()
@@ -109,8 +118,7 @@
         "stock",
         "OPENSSL_VERSION=1.0.2u",
         "OPENSSL_VERSION=3.0.2",
-        "LIBRESSL_VERSION=2.9.2",
-        "LIBRESSL_VERSION=3.5.2",
+        "LIBRESSL_VERSION=latest",
 #        "BORINGSSL=yes",
     ]:
         flags = ["USE_OPENSSL=1"]
@@ -121,6 +129,8 @@
         if ssl != "stock":
             flags.append("SSL_LIB=${HOME}/opt/lib")
             flags.append("SSL_INC=${HOME}/opt/include")
+        if "LIBRESSL" in ssl and "latest" in ssl:
+            ssl = determine_latest_libressl(ssl)
         matrix.append(
             {
                 "name": "{}, {}, ssl={}".format(clean_os(os), CC, clean_ssl(ssl)),