Add livecheck block for resource `pkg-config-wrapper` for Formulae `influxdb` and `flux`

[mohammadzainabbas]

• [x] Have you followed the guidelines for contributing?
• [x] Have you ensured that your commits follow the commit style guide?
• [x] Have you checked that there aren't other open pull requests for the same formula update/change?
• [x] Have you built your formula locally with brew install --build-from-source <formula>, where <formula> is the name of the formula you're submitting?
• [x] Is your test running fine brew test <formula>, where <formula> is the name of the formula you're submitting?
• [x] Does your build pass brew audit --strict <formula> (after doing brew install --build-from-source <formula>)? If this is a new formula, does it pass brew audit --new <formula>?

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After merging https://github.com/Homebrew/brew/pull/13613, it would be possible to use brew livecheck command for resources as well.

While augmenting brew livecheck command, I tested the functionality on multiple different resources and formulae. pkg-config-wrapper was one of the resource which could benefit from such behaviour.

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Note: you can only test this functionality properly once https://github.com/Homebrew/brew/pull/13613 is merged successfully. Simply, run brew livecheck influxdb -r and you'd see the livecheck output for resources as well.

[carlocab]

Thanks; could you reorganise your commits to match Homebrew/core style?

Here's a quick guide:

Please use the preferred commit-message style for homebrew/core. We put the name of the formula first in commit-message headings.

For new formulae:

At Homebrew, we like to put the name of the formula up front like so: foobar 7.3 (new formula).

For existing formulae:

The preferred commit message format for simple version updates is foobar 7.3 and for fixes is foobar: fix flibble matrix..

Refer to the commit style guide for more details. Also, when making further changes to your pull request, use the following guidelines to make sure that @BrewTestBot can merge your commits:

• One formula per commit; one commit per formula.
• Keep merge commits out of the pull request.