ci: correct working-directory in sdk-platform-java-verify_library_generation.yaml

[blakeli0]

sdk-platform-java-verify_library_generation.yaml has been failing due to the following errors

+ pip install --require-hashes -r hermetic_build/common/requirements.txt
ERROR: Could not open requirements file: [Errno 2] No such file or directory: 'hermetic_build/common/requirements.txt'
Error: Process completed with exit code 1.

Add sdk-platform-java as working-directory to make sure the scripts runs against the correct folder.

[gemini-code-assist]

Note

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