Add packet.ai as a new cloud GPU provider

[KavSh890]

packet.ai is missing from the comparison table. Requesting addition.

Website: https://packet.ai
Pricing page: https://packet.ai/pricing

Key on-demand rates:

• NVIDIA B200: from $3.75/hr (Dynamic), $5.90/hr (Dedicated)
• NVIDIA A100 PCIe 80GB: from $1.43/hr
• NVIDIA RTX PRO 6000 Blackwell 96GB: from $0.66/hr
• NVIDIA RTX 4090: from $0.39/hr
• NVIDIA L40S: from $0.92/hr

No egress fees. No contracts. Full root SSH access on all plans.
Happy to submit a PR to cloud-gpus.csv directly if preferred.

[sergeyk]

PR preferred