Fix SDSU ray tracer buffer overflow and modernize Python tests

[pjmaechling]

This PR addresses two compatibility issues when running the BBP on modern operating systems with stricter compilers (e.g., GCC 11, Ubuntu 22.04+).

1. SDSU Ray Tracer Segmentation Fault (ray3DJHfor.c)

• Issue: The SDSU BBtoolbox.exe binary was crashing with a segmentation fault during the high-frequency scattering generation. Modern GCC compilers flag a string buffer overflow.
• Fix: The malloc allocations for timefile and velfile on lines 205-206 were originally sized at exactly 12 and 11 bytes, which did not account for the hidden \0 null terminator required by strcpy. This caused memory corruption on strict compilers. Increased the allocation size to 80 bytes and included <stdlib.h> and <unistd.h> to resolve implicit declaration errors.

2. Python Environment Test Failure (test_python_code.py)

• Issue: The test_python_code_tests unit test was failing with a python: not found error and throwing unknown option errors for -tt. Modern Linux environments often alias to python3 exclusively, and Python 3 natively rejects mixed tabs and spaces, rendering the -tt flag obsolete.
• Fix: Updated the shell commands in test_execute_platform_bbp, test_python_code_comps, and test_python_code_tests to use sys.executable instead of hardcoded python or python3 strings, ensuring the tests always use the active Python environment. Removed the deprecated -tt flags.