Make use of SPDX-FileCopyrightText

[Vertexwahn]

Currently, all files include copyright and license information similar this way:

//
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) Contributors to the OpenEXR Project.
//

I propose to change it this way:

//
// SPDX-FileCopyrightText: Contributors to the OpenEXR Project
// SPDX-License-Identifier: BSD-3-Clause
//

OpenEXR uses already the SPDX-License-Identifier. Why not using also SPDX-FileCopyrightText. This way automatic extraction of Copyright and License information would be easier. Thee also here

Opinions?

[lgritz]

The way we currently do it is precisely as dictated by ASWF/LF request. We know that the periodic license scans that they run on our projects do recognize it the way we are doing it. This is something that would need to be put on the agenda for the ASWF TAC and see if LF admin and legal are ok with it; it's not something we mess with at the project level.