add support for windows server 2025 in productfilter

[gobalski]

wes.py aborts on every systeminfo.txt originating from a Windows Server 2025 host:

[+] Parsing systeminfo output
[-] Failed assessing Windows version 2025

determine_product() correctly extracts win = '2025' via the OS name regex, but the
if/elif chain that maps the generation to a product filter has no branch for 2025,
so execution falls through to:

else:
    raise WesException('Failed assessing Windows version {}'.format(win))

Verification

Before:

[+] Parsing systeminfo output
[-] Failed assessing Windows version 2025

After:

[+] Operating System
    - Name: Windows Server 2025
    - Generation: 2025
    - Build: 26100
    - Version: 24H2
    - Architecture: x64-based
    - Installed hotfixes (2): KB5062553, KB5063666
[+] Loading definitions
    - Creation date of definitions: 20260828
[+] Determining missing patches
[+] Filtering duplicate vulnerabilities
[!] Found vulnerabilities!