doc: requirements: avoid using pygments v2.19.0

Avoid using pygments v2.19.0 as it contains a regressions in parsing "cfg"
code-blocks.

(cherry picked from commit b114e0f)

Original-Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>
GitOrigin-RevId: b114e0f
Cr-Build-Id: 8726543930985802145
Cr-Build-Url: https://cr-buildbucket.appspot.com/build/8726543930985802145
Copybot-Job-Name: zephyr-main-copybot-downstream
Change-Id: Iccd33ed11a9b6f8b589535d041b4b2f1e498a882
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/6146534
Commit-Queue: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Bot-Commit: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>

doc/requirements.txt

@@ -4,7 +4,7 @@ sphinx
 sphinx_rtd_theme~=3.0
 sphinx-tabs
 sphinxcontrib-svg2pdfconverter
-pygments>=2.9
+pygments>=2.9,!=2.19.0
 sphinx-notfound-page
 sphinx-copybutton
 sphinx-togglebutton