Fix idempotency issue where ospfv2 module was un idempotent when set interface was set true

[Girish5tri]

Description

This PR updates documentation to clarify non-idempotent behavior of set_interface parameter in cisco.ios.ios_ospfv2 module.

Problem

The module doesn't properly document that set_interface parameter is not idempotent on subsequent runs.

When configuring passive interfaces, the module was reporting changes even when the configuration remained unchanged, it was due to the set_interface parameter being not included in state comparison.

When running a playbook with set_interface multiple times:

passive_interfaces:
  interface:
    set_interface: true  # Flag only needed for initial setup

The module shows changed and triggers unnecessary commands because the playbook configuration contains set_interface: true while the running configuration doesn't (since it's only a setup flag). This mismatch causes the module to incorrectly detect a configuration difference, leading to:

changed: true
commands: ["router ospf 1"]  # Unnecessary command triggered by false change detection

FIX

Updated module documentation to clearly indicate set_interface's non-idempotent behavior:

set_interface:
  description:
    - Suppress/Un-Suppress routing updates
    - Since set_interface is not shown in running-config, idempotency won't be maintained for subsequent playbook runs.
  type: bool

Fixes: #1130

ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME

cisco.ios.ios_ospfv2

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.06%. Comparing base (c9841b5) to head (2500b64).
Report is 37 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1137      +/-   ##
==========================================
+ Coverage   86.90%   87.06%   +0.16%     
==========================================
  Files         193      199       +6     
  Lines       11904    12083     +179     
==========================================
+ Hits        10345    10520     +175     
- Misses       1559     1563       +4     

see 81 files with indirect coverage changes