[buildbot] ci: fix ghcr.io container pushing

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/4d84082df973ce01f86dac44789f6d6075a62a8a

commit 4d84082df973ce01f86dac44789f6d6075a62a8a
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Sun May 14 20:40:08 2023 +0200

    ci: fix ghcr.io container pushing
    
    Attempt to fix following:
    
     #11 ERROR: denied: permission_denied: The requested installation does not exist.
     ------
      > pushing ghcr.io/ynezz/buildworker-v3.5.0:master with docker:
     ------
     ERROR: denied: permission_denied: The requested installation does not exist.
     Error: buildx failed with: ERROR: denied: permission_denied: The requested installation does not exist.
    
    References: https://github.com/openwrt/buildbot/actions/runs/4971701948/jobs/8899889081#step:9:191
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 .github/workflows/build-push.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/build-push.yml b/.github/workflows/build-push.yml
index 61a1c1b..d87a47d 100644
--- a/.github/workflows/build-push.yml
+++ b/.github/workflows/build-push.yml
@@ -67,7 +67,7 @@ jobs:
         id: meta
         uses: docker/metadata-action at v4
         with:
-          images: name=ghcr.io/${{ github.actor }}/build${{ matrix.container_flavor }}-v${{ env.BUILDBOT_VERSION }}
+          images: name=ghcr.io/${{ github.repository }}/build${{ matrix.container_flavor }}-v${{ env.BUILDBOT_VERSION }}
 
       - name: Login to GitHub Container Registry
         uses: docker/login-action at v2