Revert support for pinned_state from PR #4122

[weimingx]

This PR reverts the changes introduced by the cherry-pick of PR #4122 ("[ssw][ha] add support for pinned_state") in the 202511_azd branch.

Details:

• Removes the pinned_state-related parameter from VNetRouteOrch interfaces
• Reverts the behavior introduced via the cherry-picked change from sonic-net:master
• Restores the original function signature in vnetorch.cpp and vnetorch.h

Scope:

• Changes limited to:
  • orchagent/vnetorch.cpp
  • orchagent/vnetorch.h
• No unrelated code modifications

Reason:

• (<add your real reason: regression / incompatibility / breaking change / test failure, etc.>)

Verification:

• Verified code builds successfully after revert
• Confirmed pinned_state-related logic is removed
• Checked affected call paths compile and function correctly

Notes:

• This reverts only the specific functionality introduced by PR #4122
• No other features or behavior are impacted
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