Small script refactor and formula fix for large strings build.

[pierluigizagaria]

I've did some changes to the project.

• Removed old 2.x versions as the README states Some older formulas might no longer build on newer versions of Homebrew
• Added fixed scons 4.7.0 formula so we are sure that everything will work in future.
• Added the `"PREFIX=#{prefix}" build flag as the official repo does to correctly reference the stubs.
• Included the strlen build stubs when --with-large-strings is used.
• Removed the bottles part as no pre-compiled files are provided.

After some debug I found that the strlen stubs from the ufficial repo are required in order to make everything work.
Without the strlen stubs it compiles as normal, but the path does not get modified.

With this fork I was successfull to build an installer in my github actions and get the path modified.

[idleberg]

Thank you for your contribution. I want to let you know upfront that I won't be able to attend this PR for two more weeks since I'm currently on vacation. Will get back to this asap.