Happy BMO Push Day! (20210601.1)

the following changes have been pushed to bugzilla.mozilla.org:

(tag: https://github.com/mozilla-bteam/bmo/tree/release-20210601.1)

https://bugzil.la/1690203 : Automatically set priority to P1 when severity is set to S1
https://bugzil.la/1712619 : [GITHUBAUTH] Use authorization header instead of access_token query parameter when retrieving email addresses
https://bugzil.la/1713054 : Add “see also” support for ideas.mozilla.org
https://bugzil.la/1713599 : Add a card to the bug-creation flow directing user feedback to ideas.mozilla.org