Mark the source directory as safe

See https://github.blog/2022-04-12-git-security-vulnerability-announced/
for context. git now refuses to handle repositories which don't belong
to the current user by default; such repositories need to be
explicitly marked as safe, in the global configuration for the current user.

This fixes the failing release job.

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

Dockerfile.dapper

@@ -9,6 +9,8 @@ ENV DAPPER_OUTPUT=${DAPPER_SOURCE}/output PATH=${DAPPER_SOURCE}/bin/:${PATH}
 
 WORKDIR ${DAPPER_SOURCE}
 
+RUN git config --global --add safe.directory ${DAPPER_SOURCE}
+
 # Override the Helm deployment scripts
 COPY deploy_helm /opt/shipyard/scripts/lib/