fix(renovate): overridepostUpdateOptions in renovate configuration

[liby]

Motivation

This PR addresses an issue we've been encountering with our Renovate configuration, where the pnpm dedupe command inadvertently triggers the postinstall script, leading to a composer: not found error in our PRs initiated by Renovate.

Upon investigation, we found that the pnpm install command, which should theoretically not trigger postinstall due to the --ignore-scripts flag, was not the source of the issue. Instead, the postinstall script was being executed during the pnpm dedupe command.

Further investigation revealed that the pnpm dedupe command was being run due to the postUpdateOptions setting in the https://github.com/RightCapitalHQ/renovate-config that we're extending from. This setting includes pnpmDedupe, which is why pnpm dedupe is being executed.

In the context of Renovate's dependency updates, we do not need to run postinstall, and the execution of composer install within postinstall is causing issues due to the absence of Composer in the Renovate environment.

To temporarily resolve the composer: not found issue and prevent the unwanted execution of postinstall, this PR overrides the postUpdateOptions in our repository's Renovate configuration, removing pnpmDedupe

[liby]

This will be automatically fixed when renovatebot/renovate#24505 is merged.