updated pyopenssl version to fix dependency version conflict

The conflict is caused by:
    The user requested cryptography==41.0.3
    pyopenssl 22.1.0 depends on cryptography<39 and >=38.0.0

src/install/requirements_backend.txt

@@ -3,7 +3,7 @@ docker==6.0.1
 MarkupSafe==2.1.1
 networkx==2.6.3
 Pillow==9.3.0
-pyopenssl==22.1.0
+pyopenssl==23.2.0
 pyyaml==6.0.1
 
 # FIXME This is only needed by the compare/file_header plugin