build: [#42309] Runner with Kubernetes executor

This change removes the explicit tags that forces these jobs to run on
the deprecated Gitlab Runners with the Docker executor. Without this, the
jobs will run on runners with the "Run untagged jobs" configuration.
Currently the only runner with this setting is the Gitlab Runner with
the Kubernetes executor.

Author: md-magenta

Diff for: .gitlab-ci.yml

@@ -42,8 +42,6 @@ variables:
   needs: []
   image: python:3.7
   services: []
-  tags:
-    - docker
 
 TypeCheck Python:
   <<: *lint-default
@@ -88,8 +86,6 @@ Build Image:
     # We use kaniko v0.16.0 as both v0.17.0, v0.17.1, v0.18.0 and v0.19.0 contains fatal bugs.
     name: gcr.io/kaniko-project/executor:debug-v0.16.0
     entrypoint: [""]
-  tags:
-    - docker
   script:
     - echo "{\"auths\":{\"$CI_REGISTRY\":{\"username\":\"$CI_REGISTRY_USER\",\"password\":\"$CI_REGISTRY_PASSWORD\"}}}" > /kaniko/.docker/config.json
     - /kaniko/executor
@@ -108,8 +104,6 @@ Build Image:
   services: []
   before_script:
     - pip3 install -r requirements/test.txt
-  tags:
-    - docker
 
 Unit-test:
   <<: *test-default
@@ -142,8 +136,6 @@ Unit-test:
   image: alpine:3.13
   variables:
     GIT_STRATEGY: none # We do not need the source code
-  tags:
-    - docker
   before_script:
     - apk add skopeo=1.2.1-r0