fix: install 'build' with pip

Author: srevinsaju

Diff for: snap/snapcraft.yaml

@@ -61,8 +61,9 @@ parts:
     after: [classic-launch, debian-multiarch-triplet-provider-launch]
     # See 'snapcraft plugins'
     build-packages:
-      - python3-build
+      - python3-pip
     override-build: |
+      pip install build
       python -m build .
       tar -xvf dist/*.tar.gz setup.py
       rm -rf dist