ci: trim trailing whitespace

(backport <rust-lang#4050>)
(cherry picked from commit 4b21887)

Author: tgross35

.github/workflows/full_ci.yml

@@ -220,7 +220,7 @@ jobs:
           run: |
             export PATH=$HOME/.rust_solaris/bin:$PATH
             bash ./ci/run.sh ${{ matrix.target }}
-            
+
   check_cfg:
     name: "Check #[cfg]s"
     runs-on: ubuntu-22.04