Speed up LAVA test log parsing
Speed up LAVA test log parsing

Use a regular expression to parse the date-time values in each LAVA
log line rather than the expensive dateutil.parser.parse().  This is
about 20x faster.

Signed-off-by: Guillaume Tucker <e7e20b7c30f19d4ca6b81319ef81bf200369d137@collabora.com>

kernelci/kernelci-backend,kernelci/kernelci-backend