[gimp] Revert "gitlab-ci: install GIMP before running `make check`."

[Jehan <jehanp src gnome org>]

commit 97ae2811623e5a1544b0c3c666f44d505d66c942
Author: Jehan <jehan girinstud io>
Date:   Tue Jul 6 16:58:35 2021 +0200

    Revert "gitlab-ci: install GIMP before running `make check`."
    
    This reverts commit fe329adcf5f0f6837f5e741f383cf8db511a6a54.
    `make check` is meant to be working even without `make install`. Also
    this didn't fix anything anyway.

 .gitlab-ci.yml | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 47d137f822..d82f83c87d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -213,7 +213,6 @@ gimp-distcheck-debian:
         --enable-gtk-doc
         --enable-windows-installer
     - make -j "$(nproc)"
-    - make -j "$(nproc)" install
     - make -j "$(nproc)" check
     - make -j "$(nproc)" distcheck