debuginfod: PR27711 - Use -I/-X regexes during groom phase

debuginfod: PR27711 - Use -I/-X regexes during groom phase

The debuginfod -I/-X regexes operate during traversal to identify
those files in need of scanning.  The regexes are not used during
grooming.  This means that if from run to run, the regex changes so
that formerly indexed files are excluded from traversal, the data is
still retained in the index.

This is both good and bad.  On one hand, if the underlying data is
still available, grooming will preserve the data, and let clients ask
for it.  On the other hand, if the growing index size is a problem,
and one wishes to age no-longer-regex-matching index data out, there
is no way.

Let's add a debuginfod flag to use regexes during grooming.
Specifically, in groom(), where the stat() test exists, also check
for regex matching as in scan_source_paths().  Treat failure of the
regex the same way as though the file didn't exist.

Signed-off-by: Noah Sanci <nsanci@redhat.com>