internal/ci: fix reference to tool/file.RemoveAll

After the fix for https://cuelang.org/issue/1581,
the "dry run" version of `cue cmd release` ran in CI on master
started failing as it correctly spotted a mistake:

    command.release.tidyUp: undefined field: RemoveAll:
        ./goreleaser_tool.cue:47:13

RemoveAll is declared by tool/file, not tool/os.
This was likely a mistake coming from Go's os.RemoveAll.
Thanks to the bugfix, we no longer silently skip the tidyUp step.

Signed-off-by: Daniel Martí <mvdan@mvdan.cc>
Change-Id: I5cbceb87bc40f63e299ae414ac5292478be99e50
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1177345
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@gmail.com>
Reviewed-by: Paul Jolly <paul@myitcv.io>

internal/ci/goreleaser/goreleaser_tool.cue

@@ -44,7 +44,7 @@ command: release: {
 
 	let latestCUEVersion = strings.TrimSpace(latestCUE.stdout)
 
-	tidyUp: os.RemoveAll & {
+	tidyUp: file.RemoveAll & {
 		$after: latestCUE
 		path:   tempDir.path
 	}