In CI set the GC interval to 1 for Linux only

.github/workflows/ci.yml

@@ -34,6 +34,10 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
+      - name: Set the tag GC interval to 1 on linux
+        if: runner.os == 'macOS'
+        run: echo "MIRIFLAGS=-Zmiri-tag-gc=1" >> $GITHUB_ENV
+
       # We install gnu-tar because BSD tar is buggy on macOS builders of GHA.
       # See <https://github.com/actions/cache/issues/403>.
       - name: Install GNU tar