fix(install): remove duplicate act_runner prefix in runner commands

gitea/act_runner sets act_runner as the container entrypoint, so the
register and daemon subcommands must be passed directly without the
binary name prefix.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

install.sh

@@ -782,7 +782,7 @@ do_forgejo_runner_install() {
     docker run --rm \
         -v "${FORGEJO_RUNNER_DIR}:/data" \
         "${FORGEJO_RUNNER_IMAGE}" \
-        act_runner register \
+        register \
         --no-interactive \
         --instance "${forgejo_url}" \
         --token "${runner_token}" \
@@ -802,7 +802,7 @@ do_forgejo_runner_install() {
         -v /var/run/docker.sock:/var/run/docker.sock \
         -v "${FORGEJO_RUNNER_DIR}:/data" \
         "${FORGEJO_RUNNER_IMAGE}" \
-        act_runner daemon
+        daemon
 
     log_ok "Forgejo Runner started."
     echo ""