GHA: suppress git clone output

Follow-up: 8203aa6ed4

Closes #10949

.github/workflows/linux.yml

@@ -289,7 +289,7 @@ jobs:
       run: |
         sudo apt-get install apache2 apache2-dev libnghttp2-dev
         sudo python3 -m pip install impacket pytest cryptography multipart
-        git clone --depth=1 -b master https://github.com/icing/mod_h2
+        git clone --quiet --depth=1 -b master https://github.com/icing/mod_h2
         cd mod_h2
         autoreconf -fi
         ./configure PKG_CONFIG_PATH="$HOME/all/lib/pkgconfig"