Fix up string formatting/concatenation to f-strings where feasible

modules/generation_parameters_copypaste.py

@@ -269,8 +269,8 @@ Steps: 20, Sampler: Euler a, CFG scale: 7, Seed: 965400086, Size: 512x512, Model
         v = v[1:-1] if v[0] == '"' and v[-1] == '"' else v
         m = re_imagesize.match(v)
         if m is not None:
-            res[k+"-1"] = m.group(1)
-            res[k+"-2"] = m.group(2)
+            res[f"{k}-1"] = m.group(1)
+            res[f"{k}-2"] = m.group(2)
         else:
             res[k] = v