fix(mise): switch shfmt from ubi to asdf plugin

Release assets includes dots in the file names in the form of the
version string, which confuses ubi's asset parser at the moment.

config/mise/config.toml

@@ -83,7 +83,6 @@ show_tools = false
 "ubi:mikefarah/yq" = "latest"                                     # yq
 "ubi:mozilla/sccache" = "latest"                                  # sccache
 "ubi:mvdan/gofumpt" = "latest"                                    # gofumpt
-"ubi:mvdan/sh" = { version = "latest", exe = "shfmt" }            # shfmt
 "ubi:nametake/golangci-lint-langserver" = "latest"                # golangci-lint-langserver
 "ubi:opentofu/opentofu" = { version = "latest", exe = "tofu" }    # tofu
 "ubi:rclone/rclone" = "latest"                                    # rclone
@@ -109,4 +108,5 @@ lua = "latest"
 node = "lts"
 python = "latest"
 ruby = "latest"
+shfmt = "latest"
 terraform = "latest"