Race condition with sbang script

Steps to reproduce

spack -e . env depfile -o Makefile
make -Orecurse -j $(($(nproc) + 1)) SPACK_INSTALL_FLAGS=--no-check-signature

Error message

https://github.com/celeritas-project/celeritas/actions/runs/8412724587/job/23033983101

==> Error: Failed to install gmake due to FileNotFoundError: [Errno 2] No such file or directory: '/opt/spack/bin/.sbang.tmp' -> '/opt/spack/bin/sbang'
spack -c config:install_status:false -e '/home/runner/work/celeritas/celeritas' install  --no-check-signature --only-concrete --only=package /r4bpehupffuwco7tz2xsupg27nezrtpw # gmake@4.4.1%clang@=15.0.7~guile build_system=generic arch=linux-ubuntu22.04-x86_64_v3
==> Error: gmake-4.4.1-r4bpehupffuwco7tz2xsupg27nezrtpw: Package was not installed
==> Error: Installation request failed.  Refer to reported errors for failing package(s).
make: *** [Makefile:24: /home/runner/work/celeritas/celeritas/.spack-env/makedeps/install/gmake-4.4.1-r4bpehupffuwco7tz2xsupg27nezrtpw] Error 1
make: *** Waiting for unfinished jobs....

Information on your system

ubuntu-22.04 on github:
968ad02473b12f6305cc1fe19f2a0d706f171154

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output

Reproduce the failure with the shown parallel make and Spack environment commands, then inspect the sbang handling associated with /opt/spack/bin/sbang and .sbang.tmp. Done means parallel installation no longer raises the reported FileNotFoundError and the gmake target installs successfully.