Add Windows Server 2025 KMS product keys

[kallioli]

This PR adds KMS product keys for Windows Server 2025 (build 26100).

Changes

• Add KMS keys for Windows Server 2025 Standard and Datacenter editions
• Support for both Core and Desktop Experience installations

Files Modified

• kms_product_keys.json

Testing

• Keys follow the same structure as existing Windows Server versions
• Compatible with current KMS activation workflow

[ader1990]

The keys were retrieved from: https://learn.microsoft.com/en-us/windows-server/get-started/kms-client-activation-keys?tabs=windows1110ltsc%2Cwindows81%2Cserver2025%2Cversion1803#windows-server-ltsc

[ader1990]

Code looks good, thanks!

[ader1990]

Thanks for the contribution, much appreciated!