chore: fix ruff lint errors, bandit suppressions, and pin pip>=26.0

Remove unused imports (ruff F401), suppress B324 false positives on
spec-mandated MD5 in HASSH/JA3/JA3S fingerprinting, drop unused
record_version assignment in JARM parser, and pin pip>=26.0 in dev
deps to address CVE-2025-8869 and CVE-2026-1703.

decnet/prober/hassh.py

@@ -208,7 +208,7 @@ def _compute_hassh(kex: str, enc: str, mac: str, comp: str) -> str:
     Returns 32-character lowercase hex digest.
     """
     raw = f"{kex};{enc};{mac};{comp}"
-    return hashlib.md5(raw.encode("utf-8")).hexdigest()
+    return hashlib.md5(raw.encode("utf-8")).hexdigest()  # nosec B324
 
 
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