[tests] install bs4 for pywikibot CI tests

Most proofreadpage_tests were not executed due to missing bs4.
Install it for tests and code coverage with pywikibot CI action.

Change-Id: I6dd70a6e2538b19ff64d8a22a64c5c818f496f94
---
M .github/workflows/pywikibot-ci.yml
1 file changed, 13 insertions(+), 0 deletions(-)

diff --git a/.github/workflows/pywikibot-ci.yml b/.github/workflows/pywikibot-ci.yml
index ea447d1..8c91dfb 100644
--- a/.github/workflows/pywikibot-ci.yml
+++ b/.github/workflows/pywikibot-ci.yml
@@ -92,6 +92,7 @@
         pip --version
         if [ -f dev-requirements.txt ]; then pip install -r dev-requirements.txt; fi
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install "beautifulsoup4>=4.7.1"
         pip install wikitextparser
 
     - name: Generate family files

