Handle IF NOT EXISTS in CREATE WORKLOAD parsing

- Skip IF NOT EXISTS after WORKLOAD keyword before parsing name
- Fixes 03232_workload_create_and_drop/stmt3

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: kyleconroy

parser/parser.go

@@ -3758,6 +3758,17 @@ func (p *Parser) parseCreateWorkload(pos token.Position) *ast.CreateWorkloadQuer
 		p.nextToken()
 	}
 
+	// Check for IF NOT EXISTS
+	if p.currentIs(token.IF) {
+		p.nextToken()
+		if p.currentIs(token.NOT) {
+			p.nextToken()
+			if p.currentIs(token.EXISTS) {
+				p.nextToken()
+			}
+		}
+	}
+
 	// Get workload name
 	if p.currentIs(token.IDENT) || p.current.Token.IsKeyword() {
 		query.Name = p.current.Value

parser/testdata/03232_workload_create_and_drop/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt3": true
-  }
-}
+{}