fix(vpc): switch to V2 api

[Mia-Cross]

This PR updates the VPC Private Network resource to use the V2 API, making the resource regional.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 14.28571% with 6 lines in your changes missing coverage. Please review.

Please upload report for BASE (main@634f828). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
plugins/modules/scaleway_vpc_private_network.py	14.28%	6 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #69   +/-   ##
=======================================
  Coverage        ?   33.12%           
=======================================
  Files           ?       66           
  Lines           ?     4118           
  Branches        ?      801           
=======================================
  Hits            ?     1364           
  Misses          ?     2754           
  Partials        ?        0           

Flag	Coverage Δ
sanity	33.12% <14.28%> (?)

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[Gnoale]

Could you add an integration test ? 🙏