Remove avoid-version from opam files

Author: jonludlam

odoc-driver.opam

@@ -5,7 +5,6 @@ homepage: "https://github.com/ocaml/odoc"
 doc: "https://ocaml.github.io/odoc/"
 bug-reports: "https://github.com/ocaml/odoc/issues"
 license: "ISC"
-flags: [ avoid-version ]
 
 maintainer: [
   "Daniel Bünzli <daniel.buenzli@erratique.ch>"

odoc-md.opam

@@ -5,7 +5,6 @@ homepage: "https://github.com/ocaml/odoc"
 doc: "https://ocaml.github.io/odoc/"
 bug-reports: "https://github.com/ocaml/odoc/issues"
 license: "ISC"
-flags: [ avoid-version ]
 
 maintainer: [
   "Jon Ludlam <jon@recoil.org>"

odoc-parser.opam

@@ -12,7 +12,6 @@ homepage: "https://github.com/ocaml/odoc"
 bug-reports: "https://github.com/ocaml/odoc/issues"
 dev-repo: "git+https://github.com/ocaml/odoc.git"
 doc: "https://ocaml.github.io/odoc/odoc_parser"
-flags: [ avoid-version ]
 depends: [
   "dune" {>= "3.7"}
   "ocaml" {>= "4.02.0" & < "5.4"}

odoc.opam

@@ -5,7 +5,6 @@ homepage: "https://github.com/ocaml/odoc"
 doc: "https://ocaml.github.io/odoc/"
 bug-reports: "https://github.com/ocaml/odoc/issues"
 license: "ISC"
-flags: [ avoid-version ]
 
 maintainer: [
   "Daniel Bünzli <daniel.buenzli@erratique.ch>"

sherlodoc.opam

@@ -7,7 +7,6 @@ license: "MIT"
 homepage: "https://github.com/ocaml/odoc"
 doc: "https://ocaml.github.io/odoc/"
 bug-reports: "https://github.com/ocaml/odoc/issues"
-flags: [ avoid-version ]
 depends: [
   "dune" {>= "3.7"}
   "ocaml" {>= "4.0.8"}