test with pekko 1.4

Author: pjfanning

.github/workflows/nightly-1.3.yml

@@ -23,7 +23,7 @@ jobs:
       matrix:
         SCALA_VERSION: [2.12, 2.13, 3]
         JDK: [8, 17]
-        PEKKO_VERSION: ['1.3.x']
+        PEKKO_VERSION: ['1.4.x']
     steps:
       - name: Checkout
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2