Fix runtime exception in job scheduler initialization.

[shanthoosh]

Summary

Launching the job-scheduler fails with the following exception

2025-11-23 18:25:18,911 main WARN JNDI lookup class is not available because this JRE does not support JNDI. JNDI string lookups will not be available, continuing configuration. Ignoring java.lang.IllegalStateException: JNDI must be enabled by setting log4j2.enableJndiLookup=true
2025-11-23 18:25:19 INFO  Reflections:219 - Reflections took 162 ms to scan 3 urls, producing 8 keys and 20 values
Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.RuntimeException: Cannot access OPERATION_TYPE field
	at com.linkedin.openhouse.jobs.scheduler.JobsScheduler.lambda$static$0(JobsScheduler.java:109)
	at java.base/java.lang.Iterable.forEach(Iterable.java:75)
	at com.linkedin.openhouse.jobs.scheduler.JobsScheduler.<clinit>(JobsScheduler.java:100)

JobScheduler initialization discovers all sub-classes of OperationTask class through reflection and initializes them.
In #394 , a new sub-class of OperationTask viz the DatabaseOperationTask (abstract class) was added. The abstract class does not have operation-type as a field and it cannot be instantiated. This was not excluded from the JobScheduler initialization thereby causing the above failure.

Fix:

This patch addresses the problem, by excluding DatabaseOperationTask from job scheduler initialization and reenables the JobScheduler test.

Changes

• Client-facing API Changes
• Internal API Changes
• Bug Fixes
• New Features
• Performance Improvements
• Code Style
• Refactoring
• Documentation
• Tests

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Testing Done

• Manually Tested on local docker setup. Please include commands ran, and their output.
• Added new tests for the changes made.
• Updated existing tests to reflect the changes made.
• No tests added or updated. Please explain why. If unsure, please feel free to ask for help.
• Some other form of testing like staging or soak time in production. Please explain.

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Additional Information

• Breaking Changes
• Deprecations
• Large PR broken into smaller PRs, and PR plan linked in the description.

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[abhisheknath2011]

Thanks for fixing jobs scheduler initialization issue!

[abhisheknath2011]

Running this test might take time. Please check how much time it takes before enabling it.

[abhisheknath2011]

We might need to enable it through env variable and ensure that this test can be run as part of local build.