Activate save code now feature for development related tools

This will avoid having to toggle it on by default all around, see for example [2].

In effect, the configuration will be explicitely toggled appropriately by puppet (off in production, on on staging) [1]. This will avoid declaring it on in docker tools as well, so in effect abandoning [2].

That follows a suggestion from @anlambert in [3]

• [1] T4040
• [2] swh-environment!246 (closed)
• [3] !749 (closed)#inline-52894

Related to T4040

Test Plan

all tests should still be happy

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Migrated from D7393 (view on Phabricator)