Refresh Mozilla's OpenPGP signing key

Building project firefox-langpacks - firefox-langpacks-78.12.0esr-build1-linux-x86_64-a26bb9
--2021-07-09 14:04:24--  https://ftp.mozilla.org/pub/firefox/candidates/78.12.0esr-candidates/build1/SHA512SUMS.asc
Resolving ftp.mozilla.org (ftp.mozilla.org)... 13.224.7.39, 13.224.7.51, 13.224.7.54, ...
Connecting to ftp.mozilla.org (ftp.mozilla.org)|13.224.7.39|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 833 [text/plain]
Saving to: '/home/android/fdroiddata/build/org.torproject.torbrowser_alpha/tmp/tmp.zWtLGa7ZKX'

/home/android/fdroiddata/build/org.torproject.torb 100%[===============================================================================================================>]     833  --.-KB/s    in 0s      

2021-07-09 14:04:24 (62.2 MB/s) - '/home/android/fdroiddata/build/org.torproject.torbrowser_alpha/tmp/tmp.zWtLGa7ZKX' saved [833/833]

Error: File SHA512SUMS-78.12.0esr-build1 is not signed with a valid key
make: *** [Makefile:24: release-linux-x86_64] Error 1

Because:

$ gpg --no-default-keyring --keyring ../keyring/firefox.gpg --edit-key 14F26682D0916CDD81E37B6D61B7B526D98F0353
gpg (GnuPG) 2.2.19; Copyright (C) 2019 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.


pub  rsa4096/61B7B526D98F0353
     created: 2015-07-17  expires: never       usage: SC  
     trust: unknown       validity: unknown
sub  rsa4096/F1A6668FBB7D572E
     created: 2019-05-30  expired: 2021-05-29  usage: S   
[ unknown] (1). Mozilla Software Releases <release@mozilla.com>