[github-actions] Use newer cython version (Linux)
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f34d56f..68948af 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -12,7 +12,7 @@
     - name: install dependencies
       run: |
           sudo apt-get update
-          sudo apt-get install cython3
+          pip install cython
     - name: prepare environment
       run: |
           echo "target_triplet=`gcc -dumpmachine`" >> $GITHUB_ENV