Delete old pgAdmin manifest v4.28 (#9538)

manifests/p/PostgreSQL/pgAdmin-x64/4.28.0.0/PostgreSQL.pgAdmin-x64.yaml

@@ -1,26 +0,0 @@
-PackageIdentifier: PostgreSQL.pgAdmin-x64
-PackageName: pgAdmin4-x64
-Moniker: pgAdmin
-PackageVersion: 4.28.0.0
-Publisher: The PostgreSQL Global Development Group
-Author: The PostgreSQL Global Development Group
-License: The PostgreSQL Licence
-LicenseUrl: https://www.pgadmin.org/licence/
-MinimumOSVersion: 10.0.0.0
-ShortDescription: Open Source administration and development platform for PostgreSQL
-PackageUrl: https://www.pgadmin.org/
-Tags:
-- pgsql
-- sql
-- postgres
-InstallerType: exe
-Installers:
-- Architecture: x64
-  InstallerUrl: https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v4.28/windows/pgadmin4-4.28-x64.exe
-  InstallerSha256: 88acc2307eb9875cedc6c85ce8b5e8680bebe30ce1a87b84235db532cd725782
-  InstallerSwitches:
-    Silent: /verysilent
-    SilentWithProgress: /verysilent
-PackageLocale: en-US
-ManifestType: singleton
-ManifestVersion: 1.0.0