Update otel/opentelemetry-collector-contrib Docker tag to v0.126.0 (#848)

| datasource | package                              | from    | to      |
| ---------- | ------------------------------------ | ------- | ------- |
| docker     | otel/opentelemetry-collector-contrib | 0.123.0 | 0.126.0 |

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

example/go/otel/docker-compose.yaml

@@ -1,6 +1,6 @@
 services:
   otel:
-    image: otel/opentelemetry-collector-contrib:0.123.0
+    image: otel/opentelemetry-collector-contrib:0.126.0
     volumes:
       - ./otel.yml:/etc/otelcol/config.yaml