Upgrade Tor Browser to 9.5.4

Closes #17885

See merge request tails/tails!137

Currently translated at 69.1% (85 of 123 strings)

Currently translated at 68.3% (84 of 123 strings)

Currently translated at 65.9% (81 of 123 strings)

Currently translated at 65.9% (81 of 123 strings)

Currently translated at 65.9% (81 of 123 strings)

Currently translated at 61.8% (76 of 123 strings)

Currently translated at 61.0% (75 of 123 strings)

Currently translated at 61.0% (75 of 123 strings)

Currently translated at 59.3% (73 of 123 strings)

Currently translated at 90.9% (30 of 33 strings)

Translation: Tails/wiki/src/doc/first_steps/start/pc.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcdocfirst_stepsstartpcpo/es/

Currently translated at 90.9% (30 of 33 strings)

Translation: Tails/wiki/src/doc/first_steps/start/pc.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcdocfirst_stepsstartpcpo/es/

Currently translated at 17.9% (5 of 28 strings)

Translation: Tails/wiki/src/doc/first_steps/start/not_entirely.inline.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcdocfirst_stepsstartnot_entirelyinlinepo/es/

Currently translated at 94.1% (16 of 17 strings)

Translation: Tails/wiki/src/doc/first_steps/start/mac.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcdocfirst_stepsstartmacpo/es/

Currently translated at 14.7% (5 of 34 strings)

Translation: Tails/wiki/src/doc/advanced_topics/boot_options.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcdocadvanced_topicsboot_optionspo/es/

Build & test system on Bullseye and newer: use custom, fake, unversioned python packages

See merge request tails/tails!136

Release process: generate security advisory boilerplate from a template

See merge request tails/tails!128

Switch to official QEMU backport for running our test suite on Buster

See merge request tails/tails!126

The unversioned python packages are not shipped in Bullseye/sid anymore,
and even old versions are not installable anymore. This makes
vmdebootstrap and some dependencies of our test suite
(#15349, #17031) uninstallable.

So, I've uploaded to our custom APT repo some fake unversioned python packages,
which allow installing a Tails build & test environment on Bullseye/sid.

The control files added by this commit are used to generate these fake packages
with equivs-build.

While I'm at it, I'm documenting how to install vmdebootstrap on Bullseye
and newer.

refs #17858