Add repo update to basics section

Author: alecbcs

tutorial_basics.rst

@@ -35,6 +35,11 @@ Spack has some nice command line integration tools, so instead of simply prepend
 
   $ . share/spack/setup-env.sh
 
+For this tutorial we'll also pin the packages repository to ``2025.07.0`` to make use of the binary caches later on by running:
+
+.. literalinclude:: outputs/basics/repo.out
+   :language: console
+
 And now we're good to go!
 
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