Update sample app Infragistics packages to 26.1.20261.22

[Copilot]

This updates the WinForms sample applications to Infragistics 26.1.20261.22. All existing Infragistics package references in the repo’s sample projects are aligned to the 26.1 release line.

• Scope

  • Updated Infragistics PackageReference versions in all 9 sample application projects.
  • Standardized projects that previously referenced 20.1.12 and 19.2.134 onto 26.1.20261.22.

• Projects updated

  • CashflowDashboard
  • Elemental
  • IGExcel
  • IGPaint
  • INGear
  • INTune
  • InventoryManagement
  • OutlookCRM
  • ProjectManager

• Dependency change

  • Applied the version update consistently across all Infragistics WinForms packages already referenced by each sample, without changing package selection or project structure.

<PackageReference Include="Infragistics.WinForms.Shared" Version="26.1.20261.22" />
<PackageReference Include="Infragistics.WinForms.Toolbars" Version="26.1.20261.22" />
<PackageReference Include="Infragistics.WinForms.WinGrid" Version="26.1.20261.22" />