Update fixtures.py to use "127.0.0.1" for local ports (#2384) #2

Job	Run time
📦 Build the source distribution	28s
Tests on 3.8	6m 59s
Tests on 3.9	5m 48s
Tests on 3.10	6m 35s
Tests on 3.11	6m 11s
Tests on pypy3.9	9m 16s
Tests on ~3.12.0-0	3m 53s
Tests for Kafka 0.8.2.2	3m 1s
Tests for Kafka 0.9.0.1	3m 19s
Tests for Kafka 0.10.2.2	4m 38s
Tests for Kafka 0.11.0.2	4m 57s
Tests for Kafka 0.11.0.3	4m 40s
Tests for Kafka 1.1.1	5m 34s
Tests for Kafka 2.4.0	5m 29s
Tests for Kafka 2.5.0	5m 21s
Tests for Kafka 2.6.0	7m 9s
✅ Ensure the required checks passing	2s
	1h 23m 20s

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