feat(linux): set unlimited stack size for SPEC runtime scripts

[MrLinWang]

• Add ulimit -s unlimited 2>/dev/null || true to the run.sh generated by the three packaging scripts for spec2006 / spec2017 / spec2026, setting the stack limit to unlimited at script startup to reduce the risk of run failures caused by the default stack limit.
• +1 line per package script (in write_runtime_files / generate_runtime_script).
• The 2>/dev/null || true ensures the script continues executing even if the ulimit adjustment fails or the environment is
  restricted, so it is not affected by set -e.

[rezado]

I found one minor issue in the SPEC2017 packaging script: write_runtime_files() already emits
ulimit -s unlimited 2>/dev/null || true
at line 930, so the new line at line 925 causes the generated run.sh to execute the same command twice.

[MrLinWang]

I found one minor issue in the SPEC2017 packaging script: write_runtime_files() already emits ulimit -s unlimited 2>/dev/null || true at line 930, so the new line at line 925 causes the generated run.sh to execute the same command twice.

Good catch — it was indeed a duplicate. I removed the newly added line (previously at line 925) from write_runtime_files() and kept the existing ulimit -s unlimited 2>/dev/null || true, so the generated run.sh now executes it only once. Updated commit has been pushed.