Upgrade Tor Browser to 10.0.12-build2

Closes #18200

See merge request tails/tails!359

Test suite: enable garbage collection of failed transient units created by systemd-run

See merge request tails/tails!342

Test suite: add and document Cucumber tags

See merge request tails/tails!348

wiki/src/install/inc/steps/pc_boot_menu.inline.ar.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.ca.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.id.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.pl.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.ru.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.sr_Latn.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.tr.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.zh.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.
wiki/src/install/inc/steps/pc_boot_menu.inline.zh_TW.po: updating as wiki/src/install/inc/steps/pc_boot_menu.inline.de.po has changed.

- It's hasn't been that useful in the past.
- Most people shouldn't need to Boot Menu key anymore.

Currently translated at 86.3% (19 of 22 strings)

Translation: Tails/wiki/src/news/plans_for_2021.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcnewsplans_for_2021po/es/

Upgrade to Linux 5.10.13 (stable branch)

Closes #18188

See merge request tails/tails!352

Currently translated at 86.3% (19 of 22 strings)

Translation: Tails/wiki/src/news/plans_for_2021.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcnewsplans_for_2021po/es/

Currently translated at 9.3% (4 of 43 strings)

Translation: Tails/wiki/src/news/achievements_in_2020.*.po
Translate-URL: http://translate.tails.boum.org/projects/tails/wikisrcnewsachievements_in_2020po/es/

"Ensure that the workers on your team actually do the work on time"
is not possible, short of the Team manager being ready to do some
of the work themselves, which we can't assume they're able to.

So let's instead describe in more details what a manager *can*,
and probably should, be doing.

We don't track budget spent per-deliverable anymore.

We don't track time spent per-deliverable anymore.

Introduce debug=greeter kernel command line option

Closes #17084

See merge request tails/tails!353

It's not clear if RiseupLabs' address is current.

This reverts commit 56865961.

refs tails/accounting#17663

We have enough bitcoins in bitcoind for now.

Test suite: adjust to new test Git repository location

See merge request tails/tails!344

I've seen "Scenario: Erasure of memory freed by killed userspace processes" fail
once on one of my fastest tester VMs, with "Pattern coverage: 3.796% (52 MiB out
of 1372 MiB reference memory)".

Note that we previously filled 128 MiB of RAM with the known pattern,
and we find less than that here (52 MiB).

This leads me to this hypothesis:

1. When we exit from the "I kill the allocating process" step,
   the allocating process was killed (we know this) and memory poisoning
   has started.

2. When we dump the memory in "I find very few patterns in the guest's memory",
   memory poisoning has not finished its job yet: there's still 52 MiB
   of memory left to clean up.

I.e. there's a race condition between Linux memory poisoning and us dumping the
memory, which is almost always won by Linux memory poisoning, but in the failed
run I mentioned, memory poisoning lost the race.

I don't see how we can wait specifically for memory poisoning to complete before
we dump the memory, so I'm adding a 1s delay here, to increase the chances
we don't lose this race condition.

refs #18188

... to spawn a terminal instead of the greeter, which makes it easier to
debug it.

Closes #17084

Upgrade tor to 0.4.5.5-rc-1

Closes #18176

See merge request tails/tails!347

Update the deb.tails.boum.org archive signing key

See merge request tails/tails!349

Upgrade to Buster 10.8

Closes #18140

See merge request tails/tails!343

Remove Lets-Encrypt-Authority-X3.pem from our website CA bundle

Closes #18139

See merge request tails/tails!350

We need a newer snapshot because:

  [2021-02-10] linux 5.10.13-1 MIGRATED to testing (Debian testing watch)

refs #18188

… otherwise, it can't delete files that will be installed by hooks
which are run later.

We don't need them in the initramfs, let's save some space.