CI: Fix dependencies.

.drone.yml

@@ -122,6 +122,11 @@ steps:
       from_secret: email_password
   when:
     status: [ changed, failure ]
+  depends_on:
+    - GCC 10 / clang 11 (debug)
+    - Download CMake 3.12 installer
+    - GCC 9
+    - GCC 8 / clang 6
 
 ---
 name: Packages x86_64
@@ -214,7 +219,7 @@ steps:
     path: /var/cache/apt/archives
   depends_on:
     - Debian bullseye
-    - Ubuntu focal
+    - Debian buster
 
 - name: Download CMake 3.12 installer
   image: plugins/download
@@ -253,6 +258,7 @@ steps:
     path: /var/cache/apt/archives
   depends_on:
     - Debian bullseye
+    - Debian buster
     - Ubuntu focal
     - Download CMake 3.12 installer
 
@@ -307,3 +313,9 @@ steps:
       from_secret: email_password
     when:
     status: [ changed, failure ]
+  depends_on:
+    - Debian bullseye
+    - Debian buster
+    - Ubuntu focal
+    - Download CMake 3.12 installer
+    - Ubuntu bionic