GitHub actions: add Fedora 45 which provides OpenSSL 4

The release of Fedora 45 will take months, but a distro shipping OpenSSL 4
is necessary to ensure persistent OpenSSL 4 compatibility.

Author: Al2Klimov

.github/workflows/linux.yml

@@ -37,6 +37,7 @@ jobs:
           - fedora:42
           - fedora:43
           - fedora:44
+          - fedora:45
 
           - opensuse/leap:15.6
           - opensuse/leap:16.0