[release/v7.5] Move package validation to package pipeline (#26816)

.pipelines/PowerShell-Packages-Official.yml

@@ -299,3 +299,9 @@ extends:
       dependsOn: [prep, mac_package, windows_package_sign, linux_package, nupkg, msixbundle]  # prep needed for BuildInfo JSON
       jobs:
       - template: /.pipelines/templates/uploadToAzure.yml@self
+
+    - stage: validatePackages
+      displayName: 'Validate Packages'
+      dependsOn: [upload]
+      jobs:
+      - template: /.pipelines/templates/release-validate-packagenames.yml@self

.pipelines/PowerShell-Release-Official.yml

@@ -216,12 +216,6 @@ extends:
           arm64: 'yes'
           enableCredScan: false
 
-    - stage: validatePackages
-      displayName: 'Validate Packages'
-      dependsOn: []
-      jobs:
-      - template: /.pipelines/templates/release-validate-packagenames.yml@self
-
     - stage: ManualValidation
       dependsOn: []
       displayName: Manual Validation
@@ -272,7 +266,6 @@ extends:
       dependsOn:
         - ManualValidation
         - ReleaseAutomation
-        - validatePackages
         - fxdpackages
         - gbltool
         - validateSdk
@@ -365,10 +358,12 @@ extends:
             This is typically done by the community 1-2 days after the release.
 
     - stage: PublishMsix
-      dependsOn: PushGitTagAndMakeDraftPublic
+      dependsOn:
+        - setReleaseTagAndChangelog
+        - PushGitTagAndMakeDraftPublic
       displayName: Publish MSIX to store
       variables:
-        ob_release_environment: Production
+        ob_release_environment: ${{ variables.releaseEnvironment }}
       jobs:
       - template: /.pipelines/templates/release-MSIX-Publish.yml@self
         parameters: