ci: Allow different configs for the same directory

[TimePrinciple]

Summary of the PR

Currently dependabot does not allow different configurations for the same directories. This workaround [1] provides a way to bypass this restriction.

[1] https://github.com/dependabot/dependabot-core/issues/1778#issuecomment-1988140219

Requirements

Before submitting your PR, please make sure you addressed the following requirements:

• [x] All commits in this PR have Signed-Off-By trailers (with git commit -s), and the commit message has max 60 characters for the summary and max 75 characters for each description line.
• [ ] All added/changed functionality has a corresponding unit/integration test.
• [ ] All added/changed public-facing functionality has entries in the "Upcoming Release" section of CHANGELOG.md (if no such section exists, please create one).
• [ ] Any newly added unsafe code is properly documented.

[epilys]

I lack context or can't remember it right now, a few words on what does this solve? Meaning, why do we want different configs?

[TimePrinciple]

I lack context or can't remember it right now, a few words on what does this solve? Meaning, why do we want different configs?

This PR addresses https://github.com/rust-vmm/vhost-device/pull/759#issuecomment-2475907177, we were trying to lower the update frequency of non-rust-vmm crates 😉

[epilys]

Gotcha, so the only way to test is to run dependabot locally or is it checked in the CI?

[TimePrinciple]

Gotcha, so the only way to test is to run dependabot locally or is it checked in the CI?

I failed to setup dependabot-core locally so eventually I end up testing the configuration in my folk, with this change, dependabot accepts the config 🫠