CAMEL-22635: Fix LogCaptureTest in camel-netty and camel-netty-http

[gnodet]

Summary

• Programmatically attach LogCaptureAppender to the logger in setUp/tearDown instead of relying on configuration.packages plugin discovery in log4j2.properties (deprecated in Log4j2 2.x)
• Remove @Disabled annotation from both camel-netty and camel-netty-http LogCaptureTest
• Clean up log4j2.properties — remove broken appender reference that caused NPE at startup
• Add @Isolated to prevent interference with other tests

Test plan

• LogCaptureTest passes in camel-netty
• LogCaptureTest passes in camel-netty-http
• CI green

[github-actions]

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[github-actions]

🧪 CI tested the following changed modules:

• components/camel-netty-http
• components/camel-netty

Full reactor (4 modules)

• Camel :: Netty
• Camel :: Netty [jar]
• Camel :: Netty HTTP
• Camel :: Netty HTTP [jar]

[apupier]

/component-test netty netty-http

[github-actions]

✅ /component-test netty netty-http tests passed successfully.

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