Update container in section headers to isc25 (#451)

Author: alecbcs

common/setup.rst

@@ -2,7 +2,7 @@
 
    If you have not done the prior sections, you'll need to start the docker image::
 
-       docker run -it ghcr.io/spack/tutorial:sc24
+       docker run -it ghcr.io/spack/tutorial:isc25
 
    and then set Spack up like this::