Bump version to v1.31.0 (#915)

Co-authored-by: thesyncim <[email protected]>

Author: github-actions[bot]

Makefile

@@ -7,7 +7,7 @@ MAKEFLAGS += --no-builtin-rules
 MAKEFLAGS += -j$(NPROCS)
 
 CURRENT_VERSION_MAJOR = 1
-CURRENT_VERSION_MINOR = 30
+CURRENT_VERSION_MINOR = 31
 CURRENT_VERSION_BUG = 0
 
 GIT_DESCRIBE := $(shell git describe)