docker: correct path for GHCR dev container build

Signed-off-by: deadprogram <ron@hybridgroup.com>

.github/workflows/docker.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           images: |
             tinygo/tinygo-dev
-            ghcr.io/${{ github.repository }}/tinygo-dev
+            ghcr.io/${{ github.repository_owner }}/tinygo-dev
           tags: |
             type=sha,format=long
             type=raw,value=latest