CI: Bump Bitcoin Core from 27.0 to 27.1

Author: kristapsk

.github/workflows/unittests.yml

@@ -10,7 +10,7 @@ jobs:
       matrix:
         os: [macos-13, ubuntu-latest]
         python-version: ["3.8", "3.12"]
-        bitcoind-version: ["0.18.0", "27.0"]
+        bitcoind-version: ["0.18.0", "27.1"]
 
     steps:
       - uses: actions/checkout@v3