ci(Caching): Increase size of sccache on Linux; load/save each Docker image
ci(Caching): Increase size of sccache on Linux; load/save each Docker image

stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila