Set the GC interval to 1 on linux, leave default elsewhere

Author: saethlin

.github/workflows/ci.yml

@@ -36,11 +36,7 @@ jobs:
 
       - name: Set the tag GC interval to 1 on linux
         if: runner.os == 'Linux'
-        run: echo "MIRIFLAGS=-Zmiri-tag-gc=10000" >> $GITHUB_ENV
-
-      - name: Disable the tag GC on non-linux
-        if: runner.os != 'Linux'
-        run: echo "MIRIFLAGS=-Zmiri-tag-gc=10000" >> $GITHUB_ENV
+        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>.