fix: replace bare except with specific exception types

[harshadkhetpal]

Summary

Replace bare except: clauses with specific exception types across 5 files (7 occurrences).

Bare except: catches all exceptions including SystemExit, KeyboardInterrupt, and GeneratorExit, which should typically propagate. Per PEP 8 (E722) and flake8-bugbear (B001):

• Sites that re-raise → except BaseException:
• Sites that swallow errors → except Exception:

Files changed:

• salt/matchers/ipcidr_match.py — 2× except Exception:
• salt/roster/dir.py — 1× except Exception:
• salt/modules/x509.py — 2× except BaseException: (has raise)
• salt/beacons/__init__.py — 1× except Exception:
• salt/states/saltmod.py — 1× except Exception:

# Before
except:

# After (no re-raise)
except Exception:

# After (with re-raise)
except BaseException:

Testing

No behavior change — style/correctness fix only.