SCM - disable variable line height in the input field (microsoft#250802)

Author: lszomoru

src/vs/workbench/contrib/scm/browser/scmViewPane.ts

@@ -1561,6 +1561,7 @@ class SCMInputWidgetEditorOptions {
 		return {
 			...getSimpleEditorOptions(this.configurationService),
 			...this.getEditorOptions(),
+			allowVariableLineHeights: false,
 			dragAndDrop: true,
 			dropIntoEditor: { enabled: true },
 			formatOnType: true,