test: flaky TestOTLPGRPCLogsClientIP

[endorama]

From CI logs:

=== RUN   TestOTLPGRPCLogsClientIP
    otlp_test.go:508:   []any{
          	map[string]any{
          		... // 2 identical entries
          		"agent.name.text":             []any{string("android/java")},
          		"agent.version":               []any{string("unknown")},
        - 		"client.geo.city_name":        []any{string("dynamic")},
        - 		"client.geo.continent_name":   []any{string("Europe")},
        - 		"client.geo.country_iso_code": []any{string("SE")},
        - 		"client.geo.country_name":     []any{string("Sweden")},
        - 		"client.geo.location":         []any{string("dynamic")},
        - 		"client.geo.region_iso_code":  []any{string("dynamic")},
        - 		"client.geo.region_name":      []any{string("dynamic")},
          		"client.ip":                   []any{string("89.160.20.128")},
          		"data_stream.dataset":         []any{string("apm.app.unknown")},
          		... // 19 identical entries
          	},
          }
        
        Test failed. Run `make check-approvals` to verify the diff.
        
    server.go:144: log file: /home/runner/work/apm-server/apm-server/systemtest/logs/TestOTLPGRPCLogsClientIP/apm-server