[global] Change license to GPL-2.0 across all files

[arif-ali]

Related: #3705

---

Please place an 'X' inside each '[]' to confirm you adhere to our Contributor Guidelines

• Is the commit message split over multiple lines and hard-wrapped at 72 characters?
• Is the subject and message clear and concise?
• Does the subject start with [plugin_name] if submitting a plugin patch or a [section_name] if part of the core sosreport code?
• Does the commit contain a Signed-off-by: First Lastname [email protected]?
• Are any related Issues or existing PRs properly referenced via a Closes (Issue) or Resolved (PR) line?
• Are all passwords or private data gathered by this PR obfuscated?

[packit-as-a-service]

Congratulations! One of the builds has completed. 🍾

You can install the built RPMs by following these steps:

• sudo yum install -y dnf-plugins-core on RHEL 8
• sudo dnf install -y dnf-plugins-core on Fedora
• dnf copr enable packit/sosreport-sos-3712
• And now you can install the packages.

Please note that the RPMs should be used only in a testing environment.

[TurboTurtle]

Please hold, pending discussion in #3705 that I will update.

[arif-ali]

This is based on the work we have already done in Debian packaging, so just mimicking here. The Debian Developers is what made this change, to reflect the contributions.

[TurboTurtle]

LGTM. I'll make sure to call this out specifically in the release notes.