feat: alternative fingerprint rules count once (4.8.0)

Discovery compares drivers by score divided by the most a driver could
score, and that maximum summed every positive rule. Rules that never
match together, such as one vendor's landing page or another's, made a
driver that knows several vendors lose to one that knows none:
napalm-redfish's Supermicro landing page scored 6 of 41 and lost to a
bare "linux" in the same BMC's SNMP sysDescr, 5 of 18.

FingerprintRule gets an optional group. rules_max_weight() sums the
positive rules and counts each group once, with its strongest rule.
Existing rules have no group and count as before.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "napalm-device-types"
-version = "4.7.1"
+version = "4.8.0"
 description = "Abstract device-type base classes for NAPALM drivers"
 readme = "README.md"
 requires-python = ">=3.10"