Merge #53466

53466: roachtest: fetch redacted logs r=knz a=tbg

To polish redacted logs, change roachtest to collect redacted logs by
default. The unredacted logs (along with heap profiles, etc) are
retained in the artifacts as well to make sure we're not adding
debugging friction during the stability period.

All engineers are encouraged to default to using the redacted logs
(which are combined, and thus likely more ergonomical to use on
average) and to send PRs for any issues they observe.

The resulting file structure here is as follows:

```
$ ls artifacts/acceptance/multitenant/run_1/logs/
1.cockroach.log  1.unredacted/    2.cockroach.log  2.unredacted/    [...]
```

Release justification: testing-only change
Release note: None

Co-authored-by: Tobias Grieger <tobias.b.grieger@gmail.com>

pkg/cmd/roachtest/cluster.go

@@ -1488,12 +1488,28 @@ func (c *cluster) FetchLogs(ctx context.Context) error {
 
 	// Don't hang forever if we can't fetch the logs.
 	return contextutil.RunWithTimeout(ctx, "fetch logs", 2*time.Minute, func(ctx context.Context) error {
-		path := filepath.Join(c.t.ArtifactsDir(), "logs")
+		path := filepath.Join(c.t.ArtifactsDir(), "logs", "unredacted")
 		if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
 			return err
 		}
 
-		return execCmd(ctx, c.l, roachprod, "get", c.name, "logs" /* src */, path /* dest */)
+		if err := execCmd(ctx, c.l, roachprod, "get", c.name, "logs" /* src */, path /* dest */); err != nil {
+			log.Infof(ctx, "failed to fetch logs: %v", err)
+			if ctx.Err() != nil {
+				return err
+			}
+		}
+
+		if err := c.RunE(ctx, c.All(), "mkdir -p logs/redacted && ./cockroach debug merge-logs --redact logs/*.log > logs/redacted/combined.log"); err != nil {
+			log.Infof(ctx, "failed to redact logs: %v", err)
+			if ctx.Err() != nil {
+				return err
+			}
+		}
+
+		return execCmd(
+			ctx, c.l, roachprod, "get", c.name, "logs/redacted/combined.log" /* src */, filepath.Join(c.t.ArtifactsDir(), "logs/cockroach.log"),
+		)
 	})
 }