Update version, changelog, release notes for 1.2.0-rc1 (#1927)

Author: anamnavi

CHANGELOG/preview.md

@@ -1,5 +1,10 @@
 # Preview Changelog
 
+## [1.2.0-rc1](https://github.com/PowerShell/PSResourceGet/compare/v1.2.0-preview5..v1.2.0-rc1) - 2026-01-14
+
+## Bug fix
+- `WhatIf` parameter should respect provided value instead of simply checking presence (#1925)
+
 ## [1.2.0-preview5](https://github.com/PowerShell/PSResourceGet/compare/v1.2.0-preview4..v1.2.0-preview5) - 2025-12-05
 
 ### New Features

src/Microsoft.PowerShell.PSResourceGet.psd1

@@ -50,7 +50,7 @@
         'usres')
     PrivateData = @{
         PSData = @{
-            Prerelease   = 'preview5'
+            Prerelease   = 'rc1'
             Tags         = @('PackageManagement',
                 'PSEdition_Desktop',
                 'PSEdition_Core',
@@ -60,6 +60,11 @@
             ProjectUri   = 'https://go.microsoft.com/fwlink/?LinkId=828955'
             LicenseUri   = 'https://go.microsoft.com/fwlink/?LinkId=829061'
             ReleaseNotes = @'
+## 1.2.0-rc1
+
+## Bug fix
+- `WhatIf` parameter should respect provided value instead of simply checking presence (#1925)
+
 ## 1.2.0-preview5
 
 ### New Features