feat: replaced pysnmplib with lextudio's pysnmp v7.1.8

[gmaiyani-crest]

Description

Adding support of python v3.13 and migrating from pysnmplib to lextudio's pysnmp v7.1.8

• Replaced pysnmplib with lextudio’s pysmp v7.1.8
• Replaced pysnmp-pyasn1 to lextudio's pyasn1
• Replaced pysnmp-pysmi to lextudio's pysmi
• Included pysnmpcrypto (maintained by lextudio's) for stronger crypto algorithms with pysnmp v6+
• Made SC4SNMP compatible with Python 3.13
• Updated SNMP walk implementation from bulkCmd to custom multi_bulk_walk_cmd
• Introduced deploymentUser in values.yaml to make the sc4snmp entirely compatible with lextudio's pysnmp.
• Added DEPLOYMENT_USER variable for Docker Compose deployment.
• Introduces multi_bulk_walk_cmd to walk multiple OID trees simultaneously with lexicographic mode control per varbind.

Notes

Added custom multi_bulk_walk_cmd function for Multi-Varbind SNMP Walking.

Why?

• bulk_walk_cmd supports only a single varbind at a time and already includes lexicographic mode handling.
  However, to achieve the same behavior for multiple varbinds (from different OID subtrees), each varbind must be walked separately in sequence.
• Current bulk_cmd of lextuido's pysnmp does not support lexicographic option as a result we can not use bulk_cmd of lextudio's pysnmp for the same purpose.
• The new custom multi_bulk_walk_cmd addresses this by allowing multiple varbinds to be walked in parallel within a single session, maintaining lexicographic consistency while significantly reducing network roundtrips and improving overall efficiency as compare to previous bulkCmd.
• Feature request PR for adding multi_bulk_walk_cmd at Lextudio — raised here: [PR-LINK]

Key Changes

• Added multi_bulk_walk_cmd function for parallel walking of multiple OID subtrees
• Implemented lexicographic mode control for each varbind
• Restored etingof's bulkCmd multi-varbind with lexicographic capability with modern async/await patterns
• Implemented precise maxRows handling that counts actual OIDs (not iterations) with automatic truncation
• Added per-varbind completion tracking for independent state management

Type of change

Please delete options that are not relevant.

• Dependency update
• New feature
• Refactor/improvement
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Checklist

• My commit message is conventional
• I have run pre-commit on all files before creating the PR
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have checked my code and corrected any misspellings

[github-actions]

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[omrozowicz-splunk]

Looks good, please check my comments ☺️ Are we on more or less the same level of unit tests coverage as before?

[gmaiyani-crest]

Looks good, please check my comments ☺️ Are we on more or less the same level of unit tests coverage as before?

Yes, the coverage is the same as before.