chore: use package-ci/ubuntu:v3.6.0 image for Linux (#449)

Author: sindharta

.yamato/StreamingImageSequence.metafile

@@ -16,14 +16,14 @@ platforms:
   - platform_type: &platform_linux
       name: linux
       type: Unity::VM::GPU
-      image: package-ci/ubuntu:v2.0.0
+      image: package-ci/ubuntu:v3.6.0
       flavor: b1.medium
       cmd_prefix: DISPLAY=:0.0
 
 pack_platform: &pack_platform_linux
   name: linux
   type: Unity::VM
-  image: package-ci/ubuntu:v2.0.0
+  image: package-ci/ubuntu:v3.6.0
   flavor: b1.medium
 
 publish_platform: *platform_win