chore(linters): Enforce import hrouping with gci linter

[paulojmdias]

Summary

This PR updates golangci-lint to enforce proper import grouping using the gci linter. The import sections are now structured as follows:

• Standard → Go built-in packages (e.g., fmt, time).
• Default → Third-party dependencies (e.g., github.com/likexian/whois).
• Local → github.com/influxdata/telegraf modules.

The following command to fix all the modules with this linter can be executed like below. I will wait for the repo maintainers feedback to run this linter command to fix all the code needed in the repo.

gci write -s standard -s default -s localmodule .

Checklist

• No AI generated code was used in this PR

Related issues

The discussion comes from the following PR comment: #16509 (comment)

[Hipska]

Usually the PR to enable a linter also includes fixes to all the files not compliant, so the CI succeeds. If there are too many changes to be done, they are put in different preceding PRs, but I don't this is needed in this case as it should normally only be a small change in the top section of the file.

Examples

[zak-pawel]

@paulojmdias
As @Hipska mentioned, we either enable a new linter while fixing all its findings in a single PR or, if there are many findings, we first fix everything across multiple PRs and then enable the linter at the end.

[paulojmdias]

@zak-pawel @Hipska I pushed the changes needed either way.

Please review and let me know if it is really needed to split it into multiple PRs.

[zak-pawel]

Looks good! Thanks!

[Hipska]

Great addition which will keep all the code consistent!

[telegraf-tiger]

Download PR build artifacts for linux_amd64.tar.gz, darwin_arm64.tar.gz, and windows_amd64.zip.
Downloads for additional architectures and packages are available below.

☺️ This pull request doesn't significantly change the Telegraf binary size (less than 1%)

📦 Click here to get additional PR build artifacts

Artifact URLs

DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz

[srebhan]

Thanks for the epic work @paulojmdias!

[paulojmdias]

Thanks for the epic work @paulojmdias!

You're welcome 💪