Make it more obvious from the titles of longitudinal plots with flags that

the flag only applies to the head version, not the base version.

Author: Yhg1s

bench_runner/plot.py

@@ -330,9 +330,11 @@ def get_comparison_value(ref, r, base):
             r for r in results if list(r.parsed_version.release[0:2]) == version
         ]
 
-        subtitle = f"Python {cfg['version']}.x vs. {cfg['base']}"
         if len(cfg["flags"]):
-            subtitle += f" ({','.join(cfg['flags'])})"
+            titleflags = f" ({','.join(cfg['flags'])})"
+        else:
+            titleflags = ""
+        subtitle = f"Python {cfg['version']}.x{titleflags} vs. {cfg['base']}"
         ax.set_title(subtitle)
 
         first_runner = True