~seb128/thunderbird/default-profile-fix

* New upstream stable release (78.1.1build1) (LP: #1888157)
  - debian/config/branch.mk
* Bump build dependency on rustc >= 1.41.0 and cargo >= 0.42
  - debian/control{,.in}
* Bump build dependency on nodejs >= 10.21
  - debian/control{,.in}
* Bump build dependency on nasm >= 2.14.02
  - debian/control{,.in}
* Bump build dependency on debhelper >= 9
  - debian/compat
  - debian/control{,.in}
* Remove build dependency on python2
  - debian/control{,.in}
* Update cbindgen to 0.14.3
  - debian/build/create-tarball.py
* Build required icudt67b.dat on s390x with /usr/sbin/icupkg
  - debian/build/rules.mk
  - debian/control{,.in}
* Do not use system-wide sqlite3
  - debian/config/mozconfig.in
  - debian/control{,.in}
* Work around clang hanging forever when trying to optimize the build of the embedded copy of sqlite3 (LP: #1878292)
  - debian/patches/s390x-workaround-sqlite3-clang-optimization-hang.patch
* Remove obsolete config options
  - debian/config/mozconfig.in
* Allow sideloading langpacks (LP: #1866059)
  - debian/config/mozconfig.in
* Make xul-ext-lightning a transitional empty package, now that calendar functionality is part of the Thunderbird core
  - debian/build/rules.mk
  - debian/control{,.in}
  - debian/rules
* Separately installed blocklist.xml was removed
  - debian/thunderbird.install.in
* Install WeTransfer extension to the features directory
  - debian/thunderbird.install.in
* Add the following locales: af, en-CA, fa, ja-JP-mac, pa-IN, th
  - update debian/config/locales.{all,shipped}
* Remove upstreamed patch
  - debian/patches/nss_disable_fips_enabled_flag.patch
* Update and rename patch to selectively reduce debug info level
  - debian/patches/reduce-rust-debuginfo-on-selected-architectures.patch
* Refresh patches
  - debian/patches/rust-drop-dll-checksums.patch
  - debian/patches/support-coinstallable-trunk-build.patch