Use TZDIR as override lookup path

The TZDIR environment variable override the lookup paths and does not
append them. This patch fixes that behavior and is a follow-up on:

containers#1772

Ref: containers/podman#21063 (comment)

Signed-off-by: Sascha Grunert <sgrunert@redhat.com>

pkg/config/config_local.go

@@ -67,11 +67,11 @@ func (c *ContainersConfig) validateTZ() error {
  "/etc/zoneinfo",
  }
 
- // Allow using TZDIR per:
+ // Allow using TZDIR to override the lookupPaths. Ref:
  // https://sourceware.org/git/?p=glibc.git;a=blob;f=time/tzfile.c;h=8a923d0cccc927a106dc3e3c641be310893bab4e;hb=HEAD#l149
  tzdir := os.Getenv("TZDIR")
  if tzdir != "" {
- lookupPaths = append(lookupPaths, tzdir)
+ lookupPaths = []string{tzdir}
  }
 
  for _, paths := range lookupPaths {