fix(codersdk/licenses.go): read trial claim instead of misspelled trail (#28014)

## What this fixes

`codersdk.License.Trial()` looked up the JWT claim `"trail"` (a typo)
instead of `"trial"`, the actual claim name set by license issuance
(`enterprise/coderd/license/license.go`). Since no license contains a
`"trail"` claim, the method always returned `false`.

The only consumer is `coder licenses list` (via
`cli/cliutil/license.go`), so the CLI never reported a license as a
trial even when it was one. The web UI is unaffected because it reads
`claims.trial` directly.

## Changes

- Read the `"trial"` claim in `License.Trial()`.

## Testing

- `go build` / `go vet` on `codersdk` and `cli/cliutil`.
- `go test -run 'TestLicensesListFake|TestLicensesListReal'
./enterprise/cli` passes.

codersdk/licenses.go

@@ -57,8 +57,8 @@ func (l *License) ExpiresAt() (time.Time, error) {
 }
 
 func (l *License) Trial() bool {
-	if trail, ok := l.Claims["trail"].(bool); ok {
-		return trail
+	if trial, ok := l.Claims["trial"].(bool); ok {
+		return trial
 	}
 	return false
 }