deps.ffmpeg: Fix Visual Studio ID/version for librist

[RytoEX]

Description

The year/ID component of the Visual Studio display name is not always the fourth token. As far as I can tell, it is always the last token, so we can just get that. This is what we do in Setup-Target.ps1.

Motivation and Context

See also:

• deps.windows: Update dependencies for CMake 3.0 upgrade #174
• utils.pwsh: Fix CMake error with VS Build Tools #178

How Has This Been Tested?

I checked the syntax locally with a $VisualStudioData set to a copy of "Visual Studio Build Tools 2022", which is the known offender for the current syntax.

PS C:\> $VisualStudioData

InstanceId          : a63227f3
DisplayName         : Visual Studio Build Tools 2022
InstallationVersion : 17.10.35027.167
InstallationPath    : C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools
InstallDate         : 5/30/2023 1:17:32 PM

PS C:\> ($VisualStudioData.DisplayName -split ' ')[3]
Tools
PS C:\> ($VisualStudioData.DisplayName -split ' ')[-1]
2022

I did not do a full run of the build script, but I did not think it required here.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.