Stdlib Dependency Update pipeline should not wait for GraalVM checks

[dilanSachi]

Description:
In the current implementation of stdlib update pipeline [1], the bot is waiting for all the checks to merge an update PR instead of wiating only for required checks. We need to improve this as graalvm checks consume a lot of time.

[1] https://github.com/ballerina-platform/ballerina-release/blob/5e1713c7adc653b8e243ace790c83b2d934623b8/.github/workflows/update_dependency_version.yml