Update Cartographer supply chains

Author: ThomasVitale

.github/workflows/release.yml

@@ -6,7 +6,7 @@ env:
   COSIGN_EXPERIMENTAL: 1
   REGISTRY: ghcr.io
   IMAGE_NAME: ${{ github.repository }}
-  VERSION: 0.3.0
+  VERSION: 0.3.1
 
 jobs:
   build:

README.md

@@ -45,7 +45,7 @@ You can install the Kadras package repository in a dedicated namespace using `kc
 ```shell
 kubectl create namespace carvel-packages
 kctrl package repository add -r kadras-repo \
-    --url ghcr.io/arktonix/kadras-packages:0.3.0 \
+    --url ghcr.io/arktonix/kadras-packages:0.3.1 \
     -n carvel-packages
 ```