[XS] Change in flashrom[main]: meson: Update CI script to enforce building man pages and docs

[Anton Samsonov (Code Review)]

Attention is currently required from: Anastasia Klimchuk, Anton Samsonov, Thomas Heijligen.

Anton Samsonov has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/81665?usp=email )

Change subject: meson: Update CI script to enforce building man pages and docs
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Patch Set 3: Code-Review+1

(1 comment)

Patchset:

PS3: 
Although I get all kinds of build and testing errors when running `test_build.sh`
(with both `make` and `meson`, mainly because of running on non-x86 architecture,
while the scenario tries to build x86-specific stuff unconditionally, as well
as do some unit-testing that mostly segfaults and reports memory corruption —
the situation I need much more time to investigate on wider range of systems),
this change itself looks fine — the documentation is built successfully.

I even found a small bug in my previous commit, thanks to this script! (81802)