Correct license anomalies in newly added pyproject.toml

[phillxnet]

The recently added poetry build system is build around a pyproject.toml file which has the following entries in the top level "tool.poetry" setcion:

• In subsection classifiers we have:

"License :: OSI Approved :: GNU General Public License v2 or later (GPLv2+)",

• In the top level of tool.poetry we have

license = "GPL-2.0-or-later"

However we also have a reference within pyproject.toml to our "COPYING" file which dates back to the dawn of the rockstor-core repositories public release:

include = [
"COPYING", # Our GPL 3 file, but this may be redundant.
"rockstor-jslibs.tar.gz", # https://github.com/rockstor/rockstor-jslibs
"rockstor-jslibs.tar.gz.sha256sum", # sha256 of above tar.gz

It is proposed that we normalise on the oldest reference or our existing COPYING file contents which is GPL-3.0 with the proviso that we add, explicitly, the "-or-later" given the vast majority of our Python source files state this within the own headers via the term: "... either version 2 of the License, or (at your option) any later version.".

I.E. we explicitly normalise, via our new pyproject.toml, on the "GPL-3.0-or-later" (See: https://spdx.org/licenses/).

It is further proposed that we indicate the mixed license nature of our rockstor-jslibs repository that our build system, via pyproject.toml, includes when building the combination of rockstor-core and rockstor-jslibs that is our distributed produce.

For reference, a recent audit of the associated rockstor-jslibs under pr:
rockstor/rockstor-jslibs#19
has produced a (currently poorly formatted) README.md with all associated licenses detailed allowing for an overview license to be established for the rockstor-jslibs repository of, in SPDX vernacular:

SPDX-License-Identifier: (MIT AND GPL-2.0-or-later AND Apache-2.0 AND GPL-2.0-only AND LGPL-3.0-or-later AND BSD-3-Clause AND ISC)

To be absolutely clear, we are not re-licensing here, just clarify the mixed license nature of the combination of rockstor-core (GPLv3 via COPYING file) and the multitude of licenses involved with our linked rockstor-jslibs repo. Plus explicitly stating our our pyproject.toml the "-or-later" bit that we have prior-art on within our source file header.

N.B. All these licenses are both FSF Free/Libre, & OSI approved according to: SPDX License List

[phillxnet]

@FroggyFlox and @Hooverdan96
Your comments on this? I see the only clear issue is if we declare "-or-later" bit. All previous releases have actually been bundled as GPL which implies all future releases anyway. But we do need to tighten up our explicit licensing, especially given the recent audit I did on rockstor-jslibs. We have a tone of licenses in that one, and it would be good to reduce them is my thinking: by dropping stuff we don't need or can do without. It would also be good to reduce the library count somewhat I think.

[phillxnet]

Closing as:
Fixed by #2449