fix(nacos): backport loopback address filtering to 2025.0.x

[coyaSONG]

Describe what this PR does / why we need it

Backports #4350 to 2025.0.x so a configured Nacos discovery network interface cannot select an IPv4 loopback address before a usable address.

Java previously parsed the condition as IPv4 || (IPv6 && !loopback), which left IPv4 addresses outside the loopback check. The corrected grouping applies !isLoopbackAddress() to both address families.

Does this pull request fix one issue?

Fixes #4362

Describe how you did it

• grouped the IPv4 and IPv6 type checks before applying the loopback predicate in NacosDiscoveryProperties.init()
• added the regression test from fix(nacos): skip loopback addresses for network interface #4350 with 127.0.0.1 before 192.168.1.10
• aligned the two related network-interface test helper conditions

Describe how to verify it

Using JDK 17.0.19:

• red-first proof: the new focused test failed on untouched production code with expected 192.168.1.10 but actual 127.0.0.1
• focused regression: 1 test passed after the fix
• directly affected classes: 8 tests passed
• complete affected module: 45 tests passed with zero failures
• Maven checkstyle: zero violations
• git diff --check passed

Commands:

./mvnw -pl spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery -am -Dtest=NacosDiscoveryPropertiesTests#initShouldSkipLoopbackAddressFromNetworkInterface -Dsurefire.failIfNoSpecifiedTests=false test
./mvnw -pl spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery -am -Dtest=NacosDiscoveryPropertiesTests,NacosAutoServiceRegistrationIpNetworkInterfaceTests -Dsurefire.failIfNoSpecifiedTests=false test
./mvnw -pl spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-nacos-discovery -am test

Special notes for reviews

This is a focused backport of the already merged 2025.1.x fix in #4350. Implementation and validation were assisted by OpenAI Codex; no human review is claimed.

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@coyaSONG

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[xuxiaowei-com-cn]

@coyaSONG

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