[Tails-l10n] Build failed in Jenkins: check_PO_master #4239

See <https://jenkins.tails.boum.org/job/check_PO_master/4239/changes>

Changes:

[intrigeri] Update the jenkins-tools submodule.

------------------------------------------
Started by an SCM change
[EnvInject] - Loading node environment variables.
Building remotely on isobuilder3 in workspace <https://jenkins.tails.boum.org/job/check_PO_master/ws/>
Wiping out workspace first.
Cloning the remote Git repository
Cloning repository gitolite@???:tails
> git init <https://jenkins.tails.boum.org/job/check_PO_master/ws/> # timeout=10
Fetching upstream changes from gitolite@???:tails
> git --version # timeout=10
> git -c core.askpass=true fetch --tags --progress gitolite@???:tails +refs/heads/*:refs/remotes/origin/*
> git config remote.origin.url gitolite@???:tails # timeout=10
> git config remote.origin.fetch +refs/heads/*:refs/remotes/origin/* # timeout=10
> git config remote.origin.url gitolite@???:tails # timeout=10
Fetching upstream changes from gitolite@???:tails
> git -c core.askpass=true fetch --tags --progress gitolite@???:tails +refs/heads/*:refs/remotes/origin/*
> git rev-parse origin/master^{commit} # timeout=10
Checking out Revision 78c7e841460f27c182bbf1450eddce3886f22b84 (origin/master)
> git config core.sparsecheckout # timeout=10
> git checkout -f 78c7e841460f27c182bbf1450eddce3886f22b84
> git rev-list 7095f81f8ce8fd3fdfab06cb96f2c8b3fd9806b2 # timeout=10

[check_PO_master] $ /bin/sh -xe /tmp/hudson7123603556841607201.sh
+ /var/lib/jenkins/tools/slaves/check_po
  File "/var/lib/jenkins/tools/slaves/check_po", line 83
    return f"Can't detect expect file suffix .XX.po for '{self.fname}'."
                                                                       ^
SyntaxError: invalid syntax
Build step 'Execute shell' marked build as failure