Bump up the version to v13

Author: Nikola Knezevic

README.adoc

@@ -34,7 +34,7 @@ jobs:
     steps:
       # notice there is no checkout step
       - name: niv-updater-action
-        uses: knl/niv-updater-action@v12
+        uses: knl/niv-updater-action@v13
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 ----
@@ -124,7 +124,7 @@ jobs:
     steps:
       # notice there is no checkout step
       - name: niv-updater-action
-        uses: knl/niv-updater-action@v12
+        uses: knl/niv-updater-action@v13
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
@@ -195,7 +195,7 @@ jobs:
     steps:
       # notice there is no checkout step
       - name: niv-updater-action
-        uses: knl/niv-updater-action@v12
+        uses: knl/niv-updater-action@v13
         with:
           niv_version: '*from-nixpkgs*'
           skip_ssh_repos: true