ci: fix permissions in ci-docker workflow (#365)

Signed-off-by: Aurora Gaffney <[email protected]>

Author: agaffney

.github/workflows/ci-docker.yml

@@ -10,7 +10,7 @@ env:
   IMAGE_NAME: blinklabs/cardano-node-api
 
 permissions:
-  content: read
+  contents: read
 
 jobs:
   docker: