refactor - improve code quality - remove Static Variables

[khardikk]

Your checklist for this pull request

• [ x] I've read the guidelines for contributing to this repository
• [ x] I made sure to follow the project's coding style
• [ x] I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

This PR addresses the issue of removing static variables from the RzAsm and RzAnalysis plugins to improve code readability and maintainability, It is for the asm_sysz.c file. The changes follow the guidelines outlined in the contribution and the Developers guide.
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Test plan

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Closing issues

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