Do not run Generate API Diffs workflow on forks

[Alirexaa]

Fixes #653

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
CommunityToolkit.Aspire.EventStore	100%	100%	46	✔
CommunityToolkit.Aspire.GoFeatureFlag	100%	97%	74	✔
CommunityToolkit.Aspire.Hosting.ActiveMQ	80%	40%	100	✔
CommunityToolkit.Aspire.Hosting.ActiveMQ.MassTransit	1%	0%	14	❌
CommunityToolkit.Aspire.Hosting.Adminer	83%	50%	24	✔
CommunityToolkit.Aspire.Hosting.Azure.Dapr	67%	50%	828	➖
CommunityToolkit.Aspire.Hosting.Azure.Dapr.Redis	97%	88%	36	✔
CommunityToolkit.Aspire.Hosting.Azure.DataApiBuilder	100%	100%	22	✔
CommunityToolkit.Aspire.Hosting.Azure.StaticWebApps	100%	100%	28	✔
CommunityToolkit.Aspire.Hosting.Bun	82%	71%	54	✔
CommunityToolkit.Aspire.Hosting.Dapr	63%	51%	724	➖
CommunityToolkit.Aspire.Hosting.DbGate	96%	50%	18	✔
CommunityToolkit.Aspire.Hosting.Deno	84%	75%	72	✔
CommunityToolkit.Aspire.Hosting.EventStore	94%	100%	18	✔
CommunityToolkit.Aspire.Hosting.GoFeatureFlag	93%	50%	18	✔
CommunityToolkit.Aspire.Hosting.Golang	94%	50%	16	✔
CommunityToolkit.Aspire.Hosting.Java	69%	72%	120	➖
CommunityToolkit.Aspire.Hosting.k6	58%	12%	20	❌
CommunityToolkit.Aspire.Hosting.LavinMQ	78%	50%	18	➖
CommunityToolkit.Aspire.Hosting.LavinMQ.MassTransit	1%	0%	14	❌
CommunityToolkit.Aspire.Hosting.MailPit	91%	50%	14	✔
CommunityToolkit.Aspire.Hosting.Meilisearch	73%	57%	50	➖
CommunityToolkit.Aspire.Hosting.MongoDB.Extensions	96%	83%	36	✔
CommunityToolkit.Aspire.Hosting.Ngrok	52%	35%	82	❌
CommunityToolkit.Aspire.Hosting.NodeJS.Extensions	90%	69%	96	✔
CommunityToolkit.Aspire.Hosting.Ollama	67%	69%	162	➖
CommunityToolkit.Aspire.Hosting.PapercutSmtp	92%	50%	10	✔
CommunityToolkit.Aspire.Hosting.PostgreSQL.Extensions	98%	88%	92	✔
CommunityToolkit.Aspire.Hosting.Python.Extensions	68%	55%	90	➖
CommunityToolkit.Aspire.Hosting.RavenDB	63%	49%	136	➖
CommunityToolkit.Aspire.Hosting.Redis.Extensions	100%	80%	40	✔
CommunityToolkit.Aspire.Hosting.Rust	94%	83%	16	✔
CommunityToolkit.Aspire.Hosting.SqlDatabaseProjects	74%	64%	114	➖
CommunityToolkit.Aspire.Hosting.Sqlite	97%	91%	54	✔
CommunityToolkit.Aspire.Hosting.SqlServer.Extensions	100%	83%	36	✔
CommunityToolkit.Aspire.MassTransit.RabbitMQ	100%	100%	30	✔
CommunityToolkit.Aspire.Meilisearch	97%	92%	68	✔
CommunityToolkit.Aspire.Microsoft.Data.Sqlite	37%	27%	194	❌
CommunityToolkit.Aspire.Microsoft.EntityFrameworkCore.Sqlite	51%	50%	92	❌
CommunityToolkit.Aspire.OllamaSharp	71%	64%	98	➖
CommunityToolkit.Aspire.RavenDB.Client	60%	53%	237	➖
Summary	71% (6301 / 8893)	57% (1933 / 3382)	4011	➖

Minimum allowed line rate is 60%