run_tests_deb: try to run all steps under venv

Author: patapenka-alexey

.github/workflows/packing.yml

@@ -495,10 +495,15 @@ jobs:
         run: |
           apt install -y python3-venv
           python3 -m venv .venv
+
+      - name: Install test requirements
+        run: |
           . .venv/bin/activate
+          pip3 install -r requirements-test.txt
 
       - name: Install tarantool ${{ matrix.tarantool }}
         run: |
+          . .venv/bin/activate
           apt install -y curl
           curl -L https://tarantool.io/release/2/installer.sh | bash
           apt install -y tarantool tarantool-dev
@@ -512,23 +517,23 @@ jobs:
           path: deb_dist
 
       - name: Install the package from deb artifacts
-        run: apt install -y `pwd`/deb_dist/python3-tarantool_*.deb
+        run: |
+          . .venv/bin/activate
+          apt install -y `pwd`/deb_dist/python3-tarantool_*.deb
         env:
           DEBIAN_FRONTEND: noninteractive
 
-      - name: Install test requirements
-        run: |
-          pip3 install -r requirements-test.txt
-
       - name: Install the crud module for testing purposes
         run: |
+          . .venv/bin/activate
           curl -L https://tarantool.io/release/2/installer.sh | bash
           apt install -y tt
           pip3 install cmake==3.15.3
           tt rocks install crud
 
       - name: Run tests
         run: |
+          . .venv/bin/activate
           make test-pure-install
 
   publish_deb: