Use quote() instead of concating ' in summarize recipe

This is easier to read and verify for correctness, and also more
robust.

Author: EliahKagan

justfile

@@ -243,7 +243,7 @@ audit:
 nextest *FLAGS="--workspace":
     cargo nextest run {{ FLAGS }}
 
-summarize EXPRESSION="all()": (nextest "--workspace --run-ignored all --no-fail-fast --status-level none --final-status-level none -E '" EXPRESSION "'")
+summarize EXPRESSION="all()": (nextest "--workspace --run-ignored all --no-fail-fast --status-level none --final-status-level none -E" quote(EXPRESSION))
 
 # run nightly rustfmt for its extra features, but check that it won't upset stable rustfmt
 fmt: