[CI] CI now wants darcs..

.github/workflows/main.yml

@@ -149,7 +149,7 @@ jobs:
         run: |
           set -ex
           sudo apt-get update -qqy
-          sudo apt-get install -qqy ocaml-nox libpcre2-dev zlib1g-dev libgtk2.0-dev libmbedtls-dev ninja-build
+          sudo apt-get install -qqy darcs ocaml-nox libpcre2-dev zlib1g-dev libgtk2.0-dev libmbedtls-dev ninja-build
           curl -sSL https://github.com/ocaml/opam/releases/download/2.3.0/opam-2.3.0-x86_64-linux -o $RUNNER_TEMP/opam
           sudo install $RUNNER_TEMP/opam /usr/local/bin/opam
 

extra/github-actions/workflows/main.yml

@@ -50,7 +50,7 @@ jobs:
         run: |
           set -ex
           sudo apt-get update -qqy
-          sudo apt-get install -qqy ocaml-nox libpcre2-dev zlib1g-dev libgtk2.0-dev libmbedtls-dev ninja-build
+          sudo apt-get install -qqy darcs ocaml-nox libpcre2-dev zlib1g-dev libgtk2.0-dev libmbedtls-dev ninja-build
           curl -sSL https://github.com/ocaml/opam/releases/download/2.3.0/opam-2.3.0-x86_64-linux -o $RUNNER_TEMP/opam
           sudo install $RUNNER_TEMP/opam /usr/local/bin/opam