Add instructions for building the engine using dnf

[JustAPotota]

Adds setup instructions for Linux using dnf instead of apt-get. This was tested with Fedora 39 and it's possible that package names might be different on other distros that use dnf. Couple things to note:

• This doesn't include the optional things like valgrind and ccache
• The step in the last Required Software section also installs a few Python things (python3-pip, python3-cffi, python3-setuptools) but maybe it should go in the Python section?
• Some part of the build_engine step fails to find clang++ from the provided SDK so these instructions install Clang natively (latest version, I don't think it's possible to install just 13?) as well to work around this
• It would be nice to explicitly use the python3 command in scripts so that users don't need to alias it, but it seems to be a bigger change than just find and replace on the first line
• Building the engine throws a ton of warnings like defold/tmp/dynamo_home/ext/SDKs/linux/clang-13.0.0/bin/clang++: /lib64/libtinfo.so.5: no version information available (required by /var/home/potota/defold/tmp/dynamo_home/ext/SDKs/linux/clang-13.0.0/bin/clang++). This doesn't seem to cause issues for Defold though
  • https://bugzilla.redhat.com/show_bug.cgi?id=1875587 (libtinfo is from ncurses)

PR checklist

• Code
  • Add engine and/or editor unit tests.
  • New and changed code follows the overall code style of existing code
  • Add comments where needed
• Documentation
  • Make sure that API documentation is updated in code comments
  • Make sure that manuals are updated (in github.com/defold/doc)
• Prepare pull request and affected issue for automatic release notes generator
  • Pull request - Write a message that explains what this pull request does. What was the problem? How was it solved? What are the changes to APIs or the new APIs introduced? This message will be used in the generated release notes. Make sure it is well written and understandable for a user of Defold.
  • Pull request - Write a pull request title that in a sentence summarises what the pull request does. Do not include "Issue-1234 ..." in the title. This text will be used in the generated release notes.
  • Pull request - Link the pull request to the issue(s) it is closing. Use on of the approved closing keywords.
  • Affected issue - Assign the issue to a project. Do not assign the pull request to a project if there is an issue which the pull request closes.
  • Affected issue - Assign the "breaking change" label to the issue if introducing a breaking change.
  • Affected issue - Assign the "skip release notes" is the issue should not be included in the generated release notes.

Do I need to do anything with the checklist for a doc change like this?

[JCash]

I don't like one package manager installing more packages than the other?
We should strive for making sure the default package manager (apt) should work.

[JCash]

👍