Remove references to opam-repository-mingw

Author: Julow

Diff for: .github/workflows/build-mingw64.yml

@@ -40,9 +40,6 @@ jobs:
       - uses: ocaml/setup-ocaml@v3
         with:
           ocaml-compiler: 4.14.x
-          opam-repositories: |
-            default: https://github.com/ocaml-opam/opam-repository-mingw.git#sunset
-            opam: https://github.com/ocaml/opam-repository.git
 
       - name: Install dependencies
         run: |

Diff for: .github/workflows/build-others.yml

@@ -33,9 +33,6 @@ jobs:
         uses: ocaml/setup-ocaml@v3
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
-          opam-repositories: |
-            opam-repository-mingw: https://github.com/ocaml-opam/opam-repository-mingw.git#sunset
-            default: https://github.com/ocaml/opam-repository.git
 
       - name: Opam dependencies
         run: opam install --deps-only -t .