Update .ocamlformat to 0.20.1

Dream was using some of the removed options based on misconceptions
about what they did. Others seem to have good substitutes among the
remaining options.

For if-then-else = fit-or-vertical, see

  ocaml-ppx/ocamlformat#1997 (comment)

.ocamlformat

@@ -1,21 +1,17 @@
-version = 0.19.0
+version = 0.20.1
 profile = conventional
 
 leading-nested-match-parens = false
-align-constructors-decl = true
-align-variants-decl = true
 space-around-variants = false
 space-around-arrays = false
 space-around-lists = false
 space-around-records = false
-break-before-in = auto
 break-infix = fit-or-vertical
 break-separators = after
 space-around-records = true
-break-cases = all
+break-cases = fit-or-vertical
 cases-exp-indent = 2
 exp-grouping = preserve
-nested-match = align
 if-then-else = fit-or-vertical
 let-and = sparse
 type-decl = sparse