CI: dropped .git directory and added job to build on Buster.

debian/.gitlab-ci.yml

@@ -13,7 +13,7 @@ variables:
 .origtargz:
   script: &origtargz |
     ${ORIGTAR_CMD}
-#    rm -rf .git
+    rm -rf .git
 
 .pre_build:
   script: &pre_build |
@@ -126,3 +126,16 @@ experimental-amd64:
     - ${PDEBUILD_CMD} --architecture amd64 -- --basetgz /var/cache/pbuilder/experimental-amd64.tgz
     - ${LINTIAN_CMD}
 
+buster-amd64:
+  stage: build
+  tags:
+    - pbuilder
+    - amd64
+  dependencies: []
+  allow_failure: false
+  before_script:
+    - *pre_build
+  script:
+    - *origtargz
+    - ${PDEBUILD_CMD} --architecture amd64 -- --basetgz /var/cache/pbuilder/buster-amd64.tgz
+