[librsvg: 1/2] (#741) Switch Rust nightly to Debian testing

[Federico Mena Quintero <federico src gnome org>]

commit 31adcce3687b506096572b1cf1a6475dfb23cb17
Author: Dunja Lalic <dunja lalic gmail com>
Date:   Sat May 29 15:56:23 2021 +0200

    (#741) Switch Rust nightly to Debian testing

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 21832861..a4eca407 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -109,7 +109,7 @@ cargo_test:
     - sudo -E cargo test -- --skip loading_crash --skip reference --skip render_crash
 
 coverage:
-  image: "rustlang/rust:nightly"
+  image: "rustlang/rust:nightly-bullseye"
   stage: unit test
   needs:
     - job: check