[chore][exporter/datadog] Fix pseudoversion (#42845)

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#### Description

When DataDog/datadog-agent@c0e8c8158aa2 was committed,
https://github.com/DataDog/datadog-agent/releases/tag/comp/otelcol/otlp/testutil/v0.72.0-devel
did not exist, so on #42553 we based the pseudoversion on the preceding
tag,
https://github.com/DataDog/datadog-agent/releases/tag/comp/otelcol/otlp/testutil/v0.71.0-devel.

This made Renovate confused over at #42832 so I am bumping the base
version of the pseudoversion here so that Renovate works correctly
(right now Renovate tries to _downgrade_ to v0.72.0-devel but this
commit comes after v0.72.0-devl)

Author: mx-psi

exporter/datadogexporter/integrationtest/go.mod

@@ -4,7 +4,7 @@ go 1.24.0
 
 require (
 	github.com/DataDog/agent-payload/v5 v5.0.164
-	github.com/DataDog/datadog-agent/comp/otelcol/otlp/testutil v0.71.0-devel.0.20250908112322-c0e8c8158aa2
+	github.com/DataDog/datadog-agent/comp/otelcol/otlp/testutil v0.72.0-devel.0.20250908112322-c0e8c8158aa2
 	github.com/DataDog/datadog-agent/pkg/proto v0.71.0-devel.0.20250902202452-61c2536752eb
 	github.com/open-telemetry/opentelemetry-collector-contrib/connector/datadogconnector v0.136.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/exporter/datadogexporter v0.136.0