chore(osgen): silence gochecknoglobals on decodeEquivalentGroups lookup table

Pre-existing lint warning introduced in f95f305 (opensearch-project#844); the table is
a static codegen lookup intentionally kept package-level next to its
doc comment and the funcs that consult it.

Signed-off-by: Sean Chittenden <sean.chittenden@crowdstrike.com>

Author: sean-

cmd/osgen/resp_union.go

@@ -429,6 +429,8 @@ func deduplicateBranches(branches []unionBranch) []unionBranch {
 // so the two classes remain mutually reachable. string and bool need no group:
 // each has a single Go type, and exact GoType duplicates are already removed by
 // deduplicateBranches.
+//
+//nolint:gochecknoglobals // static lookup table; package-level so it's visible next to its doc comment and the funcs that consult it
 var decodeEquivalentGroups = [][]string{
 	{"int64", "int", "int32"},
 	{"float64", "float32"},