Added unit tests for custom resource interpreter's configuration manager

[anujagrawal699]

Description:
This PR adds comprehensive unit tests for the custom resource interpreter's configuration manager. The tests verify the core functionality of configuration management operations including script handling, merging behaviors, and dependency management.

Additions:

1. pkg/resourceinterpreter/customized/declarative/configmanager/accessor_test.go

Test Coverage:

1. pkg/resourceinterpreter/customized/declarative/configmanager/accessor.go: 30.70% → 100%

What type of PR is this?
/kind feature

Which issue(s) this PR fixes:
Fixes a part of #5470

Does this PR introduce a user-facing change?:

NONE

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[anujagrawal699]

Hi @mohamedawnallah , found some flaky tests.

[XiShanYongYe-Chang]

Hi @anujagrawal699 can you help rebase the newest master branch?

[anujagrawal699]

Hi @anujagrawal699 can you help rebase the newest master branch?

Hi @XiShanYongYe-Chang , my branch is already up to date with master. I think the test is still flaky after the fix.

[XiShanYongYe-Chang]

my branch is already up to date with master. I think the test is still flaky after the fix

I see. Thanks~ I'm going to keep an eye on it,

[XiShanYongYe-Chang]

Ask @mohamedawnallah to help take a look again.