instruct GitHub to create empty, instead of incomplete, release tarballs (via .gitattributes)

[slayoo]

PURPOSE: instruct GitHub to create empty, instead of incomplete, release tarballs (via .gitattributes)

TYPE: enhancement

KEYWORDS: release, gitmodules

SOURCE: @slayoo

DESCRIPTION OF CHANGES: Problem:

Solution: Make the auto-generated files empty (seems that disabling auto-generation entirely is not supported)

ISSUE: none ?

LIST OF MODIFIED FILES: .gitattributes added

TESTS CONDUCTED: Tested to work in another project: https://github.com/gnudatalanguage/gdl/blob/master/.gitattributes

RELEASE NOTE: minor change not affecting the proper release files, hence not needed to be mentioned in release notes

[slayoo]

FWIW, here's a link to github workflow step we use in GDL to upload submodule-aware tarballs to GitHub release pages automatically (when creating a release via GitHub website): https://github.com/gnudatalanguage/gdl/blob/144aad86a0d5846543c99b77acc193ab02e5adac/.github/workflows/main.yml#L60-L110

[weiwangncar]

The results from regression tests:

Test Type              | Expected  | Received |  Failed
= = = = = = = = = = = = = = = = = = = = = = = =  = = = =
Number of Tests        : 23           24
Number of Builds       : 60           57
Number of Simulations  : 158           150        0
Number of Comparisons  : 95           86        0

Failed Simulations are: 
None
Which comparisons are not bit-for-bit: 
None

[islas]

@weiwangncar What do you think about this? It could be useful to avoid users trying to download the wrong zip/tar files.

[weiwangncar]

@islas It seems useful and can avoid confusion. But we may want to do this in 4.8?