[chore] otlphttpexporter: speed up lifecycle tests (#14277)

#### Description

Make sure the tests use an invalid endpoint, so they don't block trying
to connect.

Before:

```
=== RUN   TestComponentLifecycle/metrics-lifecycle
=== RUN   TestComponentLifecycle/traces-shutdown
=== RUN   TestComponentLifecycle/traces-lifecycle
--- PASS: TestComponentLifecycle (90.05s)
    --- PASS: TestComponentLifecycle/logs-shutdown (0.00s)
    --- PASS: TestComponentLifecycle/logs-lifecycle (30.03s)
    --- PASS: TestComponentLifecycle/metrics-shutdown (0.00s)
    --- PASS: TestComponentLifecycle/metrics-lifecycle (30.02s)
    --- PASS: TestComponentLifecycle/traces-shutdown (0.00s)
    --- PASS: TestComponentLifecycle/traces-lifecycle (30.00s)
PASS
ok      go.opentelemetry.io/collector/exporter/otlphttpexporter 90.121s
```

After:

```
$ go test -v -run Lifecycle
=== RUN   TestComponentLifecycle
=== RUN   TestComponentLifecycle/logs-shutdown
=== RUN   TestComponentLifecycle/logs-lifecycle
=== RUN   TestComponentLifecycle/metrics-shutdown
=== RUN   TestComponentLifecycle/metrics-lifecycle
=== RUN   TestComponentLifecycle/traces-shutdown
=== RUN   TestComponentLifecycle/traces-lifecycle
--- PASS: TestComponentLifecycle (0.00s)
    --- PASS: TestComponentLifecycle/logs-shutdown (0.00s)
    --- PASS: TestComponentLifecycle/logs-lifecycle (0.00s)
    --- PASS: TestComponentLifecycle/metrics-shutdown (0.00s)
    --- PASS: TestComponentLifecycle/metrics-lifecycle (0.00s)
    --- PASS: TestComponentLifecycle/traces-shutdown (0.00s)
    --- PASS: TestComponentLifecycle/traces-lifecycle (0.00s)
PASS
ok      go.opentelemetry.io/collector/exporter/otlphttpexporter 0.045s
```

#### Link to tracking issue

No

#### Testing

Yes

#### Documentation

No

Author: axw

exporter/otlphttpexporter/metadata.yaml

@@ -11,5 +11,7 @@ status:
 
 tests:
   config:
-    endpoint: "https://1.2.3.4:1234"
+    # use an endpoint that does not resolve, to ensure
+    # connection attempts fail quickly in tests
+    endpoint: "https://testing.invalid:1234"