Merge pull request #50777 from apelisse/useful-error

Automatic merge from submit-queue (batch tested with PRs 49342, 50581, 50777)

apimachinery: Print unknown transport type

The current error message prints a pointer value rather than the actual
type, which is really not useful.

e.g.:

```
# Old:
unknown transport type: &{0xc42044a7b0 0xc4208d6dc0}

# New:
unknown transport type: *gcp.conditionalTransport
```

**What this PR does / why we need it**: Makes an error message more useful.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: related to #50775 

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

staging/src/k8s.io/apimachinery/pkg/util/net/http.go

@@ -108,7 +108,7 @@ func DialerFor(transport http.RoundTripper) (DialFunc, error) {
 	case RoundTripperWrapper:
 		return DialerFor(transport.WrappedRoundTripper())
 	default:
-		return nil, fmt.Errorf("unknown transport type: %v", transport)
+		return nil, fmt.Errorf("unknown transport type: %T", transport)
 	}
 }
 
@@ -129,7 +129,7 @@ func TLSClientConfig(transport http.RoundTripper) (*tls.Config, error) {
 	case RoundTripperWrapper:
 		return TLSClientConfig(transport.WrappedRoundTripper())
 	default:
-		return nil, fmt.Errorf("unknown transport type: %v", transport)
+		return nil, fmt.Errorf("unknown transport type: %T", transport)
 	}
 }