Use GH repo for checking out RPC and CLI

.github/workflows/nightly-system-tests.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   integration:
-    name: System Tests (Nightly)
+    name: System tests
     strategy:
       matrix:
         scenario-filter: ["^TestDappDevelop$/^.*$"]
@@ -19,7 +19,7 @@ jobs:
 
       # the soroban CLI & RPC source code to compile and run from system test
       # refers to checked out source of current git hub ref context
-      SYSTEM_TEST_SOROBAN_CLI_REF: ${{ github.workspace }}/soroban-tools
+      SYSTEM_TEST_SOROBAN_CLI_REF: https://github.com/stellar/soroban-tools.git\#main
       SYSTEM_TEST_SOROBAN_RPC_REF: https://github.com/stellar/soroban-rpc.git\#main
 
       # core git ref should be latest commit for stable soroban functionality