Tue, Jun 3, 2025, 10:49:42 AM GMT

check-whitespace: avoid alerts about upstream commits

Every once in a while, whitespace errors are introduced in Git for
Windows' rebases to newer Git versions, simply by virtue of integrating
upstream commits that do not follow upstream Git's own whitespace rule.
In Git v2.50.0-rc0, for example, 03f2915541a4 (xdiff: disable
cleanup_records heuristic with --minimal, 2025-04-29) introduced a
trailing space.

Arguably, non-actionable alerts are worse than no alerts at all, so
let's suppress those alerts that we cannot do anything about, anyway.

Signed-off-by: Johannes Schindelin <[email protected]>