qa,src: replace deprecated egrep/fgrep with grep -E/grep -F

qa,src: replace deprecated egrep/fgrep with grep -E/grep -F

egrep and fgrep are deprecated and emit warnings on modern systems:

  egrep: warning: egrep is obsolescent; using grep -E

Replace all occurrences of egrep with grep -E and fgrep with grep -F
across shell scripts, Python files, and YAML configs. These are
POSIX-defined equivalences with identical behavior.

Fixes: https://tracker.ceph.com/issues/75776
Signed-off-by: Lumir Sliva <lumir.sliva@firma.seznam.cz>