Fixed GitHub Actions CI

[tdulcet]

• Fixed GitHub Actions CI
  • Replaced unsupported macOS 13 runner with the new macOS 15 Intel runner.
  • Updated to test with Linux and macOS ARM runners.
  • Updated actions/checkout. Fixes Bump actions/checkout from 4 to 6 #343
  • Updated actions/upload-artifact. Fixes Bump actions/upload-artifact from 4 to 5 #336
• Fixed Makefile to allow building with Clang again.
• Fixed ARM builds by commenting out the unused __float128 datatype. Fixes Use portable _Float128 instead of __float128. Fix ARM64 builds. #326
• Fixed permission error with genbundle.sh script on some systems by explicitly running it with Bash.
  • Also fixed the ShellCheck errors.
• Enabled -O3 optimization.
• Updated link to AutoPrimeNet.

CC: @N-Storm