.github: disable test_mimxrt1060 workflow

[ncmiller]

On the mimxrt1060 when setting credentials via shell in verify.py, there is a good chance to encounter this failing assert:

===== Setting credentials via CLI (logging disabled) ====
[00:00:03.285,308] <err> os: ***** USAGE FAULT *****
ASSERTION FAIL [!arch_is_in_isr()] @ WEST_TOPDIR/zephyr/kernel/mutex.c:101
        mutexes cannot be used inside ISRs

The root cause is unknown, so the workflow is being temporarily disabled until it can be fixed.

Signed-off-by: Nick Miller nick@golioth.io

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 7018848):

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