Updating trixie buildd chroots to use -security

[Moritz Mühlenhoff]

Hi,
unfortunately we need to re-enable the config that trixie-security buildds pull 
in
trixie-security, the latest opendjk-21/25 security no longer work with jtreg8 
8.1 from trixie.

I'll upload a backport of 8.3 trixie-security. Since Java security releases 
only happen
quartely we can disable this again opendjk-21/25 are released.

Cheers,
        Moritz