util-linux-uuid: add conflict for new version and old compilers (#29149)

The system compiler on RHEL7 fails to build the latest linux-uuid.
```
util-linux-uuid@2.37.4%gcc@4.8.5 arch=linux-rhel7-haswell
```
results in:
```
libuuid/src/unparse.c:42:73: error: expected ';', ',' or ')' before 'fmt'
 static void uuid_fmt(const uuid_t uuid, char *buf, char const *restrict fmt)
```
It looks like it's assuming C99 by default so there may be a better way
to handle this... but this at least works

var/spack/repos/builtin/packages/util-linux-uuid/package.py

@@ -18,6 +18,8 @@ class UtilLinuxUuid(AutotoolsPackage):
     version('2.36.2', sha256='f5dbe79057e7d68e1a46fc04083fc558b26a49499b1b3f50e4f4893150970463')
     version('2.36',   sha256='82942cd877a989f6d12d4ce2c757fb67ec53d8c5cd9af0537141ec5f84a2eea3')
 
+    conflicts('%gcc@:4', when='@2.37:')
+
     depends_on('pkgconfig', type='build')
 
     provides('uuid')