ci: fix URL for submodule as relative

Use relative path for repositories to reuse main project protocol
for clonning.

.gitmodules

@@ -1,13 +1,13 @@
 [submodule "third_party/luarocks"]
 	path = cli/rocks/third_party/luarocks
-	url = https://github.com/tarantool/luarocks.git
+	url = ../luarocks.git
 	branch = luarocks-3.9.2-tarantool
 	ignore = dirty
 [submodule "third_party/cartridge-cli"]
 	path = cli/cartridge/third_party/cartridge-cli
-	url = https://github.com/tarantool/cartridge-cli.git
+	url = ../cartridge-cli.git
 	ignore = dirty
 [submodule "cli/aeon/protos"]
 	path = cli/aeon/protos
-	url = [email protected]:tarantool/aeon-api-protos.git
+	url = ../aeon-api-protos.git
 	branch = master