chore: drop rc0 pre-release tag for 0.3.0 release

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Kajal Jain <kajalj@nvidia.com>

Author: kajalj22

nemo_gym/package_info.py

@@ -17,7 +17,7 @@
 MAJOR = 0
 MINOR = 3
 PATCH = 0
-PRE_RELEASE = "rc0"
+PRE_RELEASE = ""
 
 # Use the following formatting: (major, minor, patch, pre-release)
 VERSION = (MAJOR, MINOR, PATCH, PRE_RELEASE)