1) Edit lang/en/langconfig.php and change:

-$string['decsep'] = '.';
+$string['decsep'] = ',';
...
-$string['thousandssep'] = ',';
+$string['thousandssep'] = '.';
...
-$string['localecldr'] = 'en-AU';
+$string['localecldr'] = 'es-ES';

2) Convert all features to use comma decimal separator

it has a few wrong changes, but they are minority. Execute it 3 times in a row!!!!!

ag -l '\d+\.\d+' | \
    ag '\.feature$' | \
    xargs sed -i 's/\([" |\/(-–'"'"'][0-9][0-9]*\)\(\.\)\([0-9][0-9]*\(['"'"'-–)\/%" |]\|\."\)\)/\1,\3/g'

3) Remove all the feature files that have not been modified (to save execution time):

(cannot use ag -L because of buggy behaviour, never released 

grep -LPr '\d+,\d+' | \
    ag '\.feature$' | \
    ag -v 'codechecker' | \
    xargs git rm

4) Restitute some excluded (themes blacklists) features (or behat doesn't init ok) and some false positive files too:

git co origin/BRANCH lib/tests/behat/action_menu.feature blocks/tests/behat/hide_blocks.feature blocks/tests/behat/move_blocks.feature course/tests/behat/activity_navigation.feature course/tests/behat/activity_navigation_with_restrictions.feature course/tests/behat/paged_course_navigation.feature course/tests/behat/section_visibility.feature mod/page/tests/behat/page_appearance.feature admin/tests/behat/site_administration.feature course/format/tests/behat/course_courseindex.feature course/format/tests/behat/courseindex_keyboardnav.feature mod/quiz/tests/behat/backup.feature badges/tests/behat/backpack.feature question/type/numerical/tests/behat/backup_and_restore.feature h5p/tests/behat/h5p_libraries.feature enrol/lti/tests/behat/lti_adv_resource_publication.feature enrol/lti/tests/behat/index_page.feature admin/tool/dataprivacy/tests/behat/manage_purposes.feature mod/book/tests/behat/create_chapters.feature mod/book/tests/behat/reorganize_chapters.feature 

5) Commit everything

git add . && git commit -m "NOBUG / REMOVEME: Change behat to run using localised floats"

6) Remove:
- grade/report/grader/tests/behat/ajax_grader.feature , it's being fixed @ MDL-73936
- reportbuilder/tests/behat/columnaggregationeditor.feature , it's being fixed @ MDL-73941
- mod/h5pactivity/tests/behat/grading_attempts.feature , some random results, and have verified they handle localised ok, it's being fixed @ MDL-73944
- grade/export/txt/tests/behat/export.feature and grade/export/xml/tests/behat/export.feature , because it's not clear if grades export should be localised or no, it's being decided @ MDL-73946
- question/type/numerical/tests/behat/preview.feature ,  it's a feature using decsep that, the way it's built, is incompatible with our changes. It passes ok, anyway.

git rm grade/report/grader/tests/behat/ajax_grader.feature reportbuilder/tests/behat/columnaggregationeditor.feature mod/h5pactivity/tests/behat/grading_attempts.feature grade/export/txt/tests/behat/export.feature grade/export/xml/tests/behat/export.feature question/type/numerical/tests/behat/preview.feature

7) Revert feature files that set the decimal separator themselves:

find . -name "*.feature" | \
    xargs ag -l "decsep" | \
    xargs git checkout origin/BRANCH 

8) Amend a few false positives:

sed -i 's/Section 6,2/Section 6.2/g' question/type/ddimageortext/tests/behat/backup_and_restore.feature

9) Reapply the changes to all the files that we added scenarios to (this step will change in the future, surely, it's only valid now, for the ongoing issue)

git show c93cf95278794e1d0a31285ca9b7fd2a8183c9c2 --pretty="" --name-only | \
    ag '\.feature$' | \
    xargs sed -i 's/\([" |\/(-–'"'"'][0-9][0-9]*\)\(\.\)\([0-9][0-9]*\(['"'"'-–)\/%" |]\|\."\)\)/\1,\3/g' 

10) Commit everything (amending)

git add . && git commit --amend

11) run complete behats with php80 (branch MDL-73824).

- goutte: ....
- firefox: ....