[directory authority] sandboxing breaks bwauth

Hi!

being a v3 bw auth breaks with sandboxing on 0.4.8.11:

root@ntor01:~# egrep -i '^v3bandwid|sandb' /etc/tor/torrc
V3BandwidthsFile /var/lib/tor/V3BandwidthsFile-from-bws
Sandbox 1
root@ntor01:~# ls -l /var/lib/tor/V3BandwidthsFile-from-bws
-rw-r--r-- 1 debian-tor debian-tor 4962004 Apr 18 19:45 /var/lib/tor/V3BandwidthsFile-from-bws

And:

Apr 18 19:50:00.000 [notice] Time to vote.
Apr 18 19:50:00.000 [warn] Can't open bandwidth file at configured location: /var/lib/tor/V3BandwidthsFile-from-bws
Apr 18 19:50:02.000 [warn] Can't open bandwidth file at configured location: /var/lib/tor/V3BandwidthsFile-from-bws
Apr 18 19:50:02.000 [notice] Choosing valid-after time in vote as 2024-04-18 20:00:00: consensus_set=1, last_interval=3600

Please add open for the V3BandwidthsFile to the sandboxing set.

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