refactor: remove dead InterfaceConnection functions (endpoint removed in NetBox 4.0)

The /api/dcim/interface-connections/ endpoint was superseded by the
Cables model in NetBox 4.0 and is no longer exposed by the API. Verified
against all three supported NetBox versions — 4.3.7 (minimum), 4.4.10,
and 4.5.8 all return HTTP 404 for GET /api/dcim/interface-connections/,
and the path is absent from each version's OpenAPI schema.

Consumers calling these four functions were receiving 404s, not useful
output. This was a long-standing dead branch inherited from the NetboxPS
fork that the 2026-04-17 drift audit surfaced as the last remaining
ValidateSet-parity finding (#392 item 9).

Removed:
- Functions/DCIM/Interfaces/Get-NBDCIMInterfaceConnection.ps1
- Functions/DCIM/Interfaces/New-NBDCIMInterfaceConnection.ps1
- Functions/DCIM/Interfaces/Set-NBDCIMInterfaceConnection.ps1
- Functions/DCIM/Interfaces/Remove-NBDCIMInterfaceConnection.ps1

Related cleanup:
- Functions/Helpers/_Aliases.ps1: drop Add-NBDCIMInterfaceConnection
  (the legacy alias for New-).
- Tests/DCIM.Interfaces.Tests.ps1: remove four Context blocks plus
  InterfaceConnection entries from the WhatIf/All-PageSize/Omit
  TestCases arrays. The remaining 9 Interface tests still pass.
- PowerNetbox.psd1: FunctionsToExport regenerated by deploy.ps1
  without the 4 removed functions; AliasesToExport drops
  Add-NBDCIMInterfaceConnection.

Migration: callers should use the Cables API instead. A direct cable
between two interfaces in PowerNetbox:

    New-NBDCIMCable -A_Terminations @(@{object_type='dcim.interface'; object_id=1}) `
                    -B_Terminations @(@{object_type='dcim.interface'; object_id=2})

After this commit the parity tool reports "All ValidateSets match
NetBox v4.5.8" — #392 drift backlog fully closed.

Breaking change: any caller still using {Get,New,Set,Remove}-
NBDCIMInterfaceConnection (or the Add- alias) will get a
CommandNotFoundException. In practice no such caller can exist, since
every call to the underlying endpoint has returned 404 across the
entire supported NetBox version range.

Author: ctrl-alt-automate

Functions/DCIM/Interfaces/Get-NBDCIMInterfaceConnection.ps1

@@ -2,10 +2,9 @@
 # These aliases maintain compatibility with scripts using the old Add-* naming convention
 
 Set-Alias -Name Add-NBDCIMInterface -Value New-NBDCIMInterface
-Set-Alias -Name Add-NBDCIMInterfaceConnection -Value New-NBDCIMInterfaceConnection
 Set-Alias -Name Add-NBDCIMFrontPort -Value New-NBDCIMFrontPort
 Set-Alias -Name Add-NBDCIMRearPort -Value New-NBDCIMRearPort
 Set-Alias -Name Add-NBVirtualMachineInterface -Value New-NBVirtualMachineInterface
 
 # Export aliases
-Export-ModuleMember -Alias Add-NBDCIMInterface, Add-NBDCIMInterfaceConnection, Add-NBDCIMFrontPort, Add-NBDCIMRearPort, Add-NBVirtualMachineInterface
+Export-ModuleMember -Alias Add-NBDCIMInterface, Add-NBDCIMFrontPort, Add-NBDCIMRearPort, Add-NBVirtualMachineInterface