Allow to override build date with SOURCE_DATE_EPOCH

Description

Applies a patch from Bernhard Wiedemann, from the OpenSUSE team, that makes the builds reproducible:

https://reproducible-builds.org/

API Changes and Justification

Backwards Compatible Changes

• This change introduces no API changes
• This change adds new API calls

Backwards Incompatible Changes

• This change modifies an existing API
• This change removes an existing API

If any of the Backwards Incompatible check boxes are ticked please provide a justification why this change is necessary and why it needs to be done in a backwards incompatible way.

Review Status

Please provide details on any reviews related to this change and and the associated reviewers.

added infra_general + 1 deleted label

@duncanmmacleod @karl-wette Could one of you please take a look at this?

approved this merge request

merged

mentioned in commit d29348a1

mentioned in merge request !1459 (merged)

mentioned in commit 0515e306

mentioned in merge request !1498 (merged)

mentioned in commit 5268e064

added infra_autotools label and removed infra_general label