ci: add a separate 'Install markdown' step to the gitly-compiles job

.github/workflows/ci.yml

@@ -430,10 +430,11 @@ jobs:
       run: sudo apt-get install --quiet -y libssl-dev sqlite3 libsqlite3-dev
     - name: Build V
       run: make -j2 && ./v -cc gcc -o v cmd/v
+    - name: Install markdown
+      run: ./v install markdown
     - name: Build Gitly
       run: |
         git clone --depth 1 https://github.com/vlang/gitly
-        ./v install markdown
         cd gitly
         ../v .
         ../v -autofree .