DAOS-16585 tests: Fix NLT handling of __fxstat detection #6777

Job	Run time
Create Docker images (ubuntu)	8m 55s
Create Docker images (rocky)	9m 13s
Create Docker images (fedora)	10m 4s
Create Docker images (leap.15)	12m 8s
Build DAOS (alma.8)	40m 22s
Build DAOS (alma.9)	38m 40s
Build DAOS (ARM64) (ubuntu, clang)	1s
Build DAOS (rocky.8)	38m 15s
Build DAOS (ubuntu)	34m 40s
Build DAOS (ARM64) (alma.8, clang)	1s
Build DAOS (ARM64) (leap.15, clang)	1s
Run DAOS/NLT tests (ubuntu)	24m 30s
Build DAOS in image (ubuntu, clang)	23m 28s
Build DAOS in image (ubuntu, gcc)	22m 41s
Build DAOS in image (rocky, clang)	24m 19s
Build DAOS in image (rocky, gcc)	25m 46s
Build DAOS in image (fedora, clang)	23m 7s
Build DAOS in image (fedora, gcc)	26m 53s
Build DAOS in image (leap.15, clang)	23m 36s
Build DAOS in image (leap.15, gcc)	24m 6s
	6h 50m 46s

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