chore: Update dependabot

[nabetti1720]

Issue # (if available)

n/a

Description of changes

This PR customizes Dependabot to reduce manual effort.

• Updates Cargo.lock within the scope of SemVer in Cargo.toml.
• Updates Cargo.lock for "/" and "validation/local_ping_pong_openssl", which are targeted for CI.
• Remove open-pull-requests-limit as it becomes meaningless when combining PRs.

[nabetti1720]

Could it be that leaving the PR alone for a long time has caused it to become inactive?

https://docs.github.com/en/enterprise-cloud@latest/code-security/how-tos/secure-your-supply-chain/troubleshoot-dependency-security/dependabot-updates-stopped#about-automatic-deactivation-of-dependabot-updates

[tarcieri]

Could it be that leaving the PR alone for a long time has caused it to become inactive?

Leaving which PR alone?

[nabetti1720]

Could it be that leaving the PR alone for a long time has caused it to become inactive?

Leaving which PR alone?

The PR opened by dependabot is already outdated and no longer needed. And when you asked dependabot to rebase, dependabot closed it without rebasing (because what you wanted to achieve with the PR is already outdated). I think this is also the correct behavior.

[nabetti1720]

I'm concerned that there haven't been any significant PRs for the directory "/". The interval is "daily", so I'll have to wait a day and see what happens.