Remove otel from dependabot ignore list

[rosstimothy]

The latest version of otel has fixed the data races that were preventing us from upgrading. Removing the dependencies from the ignore list so that dependabot can update them.

Changelog

Sourced from go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc's changelog.

[1.24.0/0.49.0/0.18.0/0.4.0] - 2024-02-23

This release is the last to support [Go 1.20]. The next release will require at least [Go 1.21].

Added

• Support [Go 1.22]. (#5082)
• Add support for Summary metrics to go.opentelemetry.io/contrib/bridges/prometheus. (#5089)
• Add support for Exponential (native) Histograms in go.opentelemetry.io/contrib/bridges/prometheus. (#5093)

Removed

• The deprecated RequestCount constant in go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp is removed. (#4894)
• The deprecated RequestContentLength constant in go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp is removed. (#4894)
• The deprecated ResponseContentLength constant in go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp is removed. (#4894)
• The deprecated ServerLatency constant in go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp is removed. (#4894)

Fixed

• Retrieving the body bytes count in go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp does not cause a data race anymore. (#5080)

[codingllama]

Maybe hold this in favor of #38636 ?

[rosstimothy]

#38636 can safely be applied after this change though right?