Fix a deadlock when updating the summary of a room that has a voice broadcast

[nimau]

This PR is a hotfix fixing a deadlock happening when we try to update the summary of a room that has a voice broadcast.

To reproduce this issue in the current 1.9.16, simply clear the cache and a deadlock should occur if there is a voice broadcast in a room.

[pixlwave]

PR looks good on my side, and everything is set up correctly for us to build a hotfix from.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (hotfix/1.9.16@ae87624). Click here to learn what that means.
Patch has no changes to coverable lines.

Additional details and impacted files

@@               Coverage Diff                @@
##             hotfix/1.9.16    #7300   +/-   ##
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  Coverage                 ?   11.97%           
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  Files                    ?     1634           
  Lines                    ?   161034           
  Branches                 ?    65131           
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  Hits                     ?    19291           
  Misses                   ?   141101           
  Partials                 ?      642           

Flag	Coverage Δ
uitests	55.34% <0.00%> (?)
unittests	5.95% <0.00%> (?)

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[giomfo]

LGTM
Tests are all ok