gnu: r-mice: Update to 3.15.0.

* gnu/packages/cran.scm (r-mice): Update to 3.15.0.
[propagated-inputs]: Remove r-withr.

gnu/packages/cran.scm

@@ -6645,14 +6645,14 @@ analysis of multiply imputed data sets.")
 (define-public r-mice
   (package
     (name "r-mice")
-    (version "3.14.0")
+    (version "3.15.0")
     (source
      (origin
        (method url-fetch)
        (uri (cran-uri "mice" version))
        (sha256
         (base32
-         "01fnfrr7adp29s5kic95r9q0rdznkz2pjmziyimnrqzyicyvfyzq"))))
+         "0yz88b40mpn24z40yfpxrkwrsxk362gwks3v5x69rkix1qkdsr1x"))))
     (build-system r-build-system)
     (propagated-inputs
      (list r-broom
@@ -6662,8 +6662,7 @@ analysis of multiply imputed data sets.")
            r-lattice
            r-rcpp
            r-rlang
-           r-tidyr
-           r-withr))
+           r-tidyr))
     (home-page "https://cran.r-project.org/web/packages/mice/")
     (synopsis "Multivariate imputation by chained equations")
     (description