testsuite: test `flux submit --add-file=name=DATA` #3220

Job	Run time
Generate build matrix	8s
spelling	5s
validate commits	0s
python linting	27s
bookworm - test-install	12m 13s
bookworm - 32 bit	13m 3s
noble - test-install	13m 19s
el9 - test-install	12m 48s
alpine - test-install	12m 28s
fedora40 - test-install	11m 43s
jammy - test-install	12m 18s
focal - py3.8	17m 31s
bookworm - gcc-12,content-s3,distcheck	19m 59s
fedora40 - clang-18	33m 56s
coverage	24m 33s
el8 - ascii	19m 24s
el8 - test-install	12m 51s
el8 - system,coverage	7m 34s
inception	21m 49s
flux-pmix check	13m 15s
flux-pam check	4m 37s
macos build only	2m 35s
flux-accounting check	4m 41s
flux-sched check	7m 0s
Generate docker manifest	1s
	4h 38m 18s

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