OvmfPkg: Update pipeline filenames

Details about a particular pipeline change over time - such as the
specific Linux distro or toolchain version. At the same time, the
pipeline files are directly referenced in Azure Pipelines to run the
pipeline and few users have access to change those details.

To make the files less likely to refer to outdated information over
time and reduce the need for an Azure Pipeline administrator to get
involved, the files are updated to drop specific details apart from
the host OS environment used in the pipeline.

Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>

OvmfPkg/PlatformCI/.azurepipelines/Ubuntu-GCC.yml

@@ -3,7 +3,7 @@
 #
 # Platform: OVMF
 # OS: Ubuntu
-# Toolchain: GCC5
+# Toolchain: GCC
 #
 # Copyright (c) Microsoft Corporation.
 # SPDX-License-Identifier: BSD-2-Clause-Patent

OvmfPkg/PlatformCI/.azurepipelines/Windows-VS.yml

@@ -3,7 +3,7 @@
 #
 # Platform: OVMF
 # OS: Windows
-# Toolchain: VS2022
+# Toolchain: VS
 #
 # Copyright (c) Microsoft Corporation.
 # SPDX-License-Identifier: BSD-2-Clause-Patent