Update version number to v1.21.2

ss0832 · web-flow · commit b9e712e75b83 · 2026-03-12T13:13:59.000+09:00
diff --git a/README.md b/README.md
@@ -407,7 +407,7 @@ If you use MultiOptPy in your research, please cite it as follows:
   month        = dec,
   year         = 2026,
   publisher    = {Zenodo},
-  version      = {v1.21.1},
+  version      = {v1.21.2},
   doi          = {10.5281/zenodo.18974400},
   url          = {https://doi.org/10.5281/zenodo.18974400}
 }

Original file line number	Diff line number	Diff line change
`@@ -407,7 +407,7 @@ If you use MultiOptPy in your research, please cite it as follows:`
`407`	`407`	`month = dec,`
`408`	`408`	`year = 2026,`
`409`	`409`	`publisher = {Zenodo},`
`410`		`- version = {v1.21.1},`
	`410`	`+ version = {v1.21.2},`
`411`	`411`	`doi = {10.5281/zenodo.18974400},`
`412`	`412`	`url = {https://doi.org/10.5281/zenodo.18974400}`
`413`	`413`	`}`