Remove leftover GitLab references

Clean up two .mli doc-comments and two unused static images that were
missed by the prior GitLab removal commits.

Author: mtelvers

lib/build.mli

@@ -8,8 +8,7 @@ val v :
   ([> `Built | `Checked ] Current_term.Output.t * Current.job_id option)
   Current.t
 (** Build and test all the opam packages in a given build context on the given
-    platform. [~repo] is the ID of the repository-under-test on a Git Forge
-    (e.g. GitHub or GitLab). *)
+    platform. [~repo] is the ID of the repository-under-test on GitHub. *)
 
 val make_build_spec :
   base:Current_docker.Raw.Image.t ->

lib/cluster_build.mli

@@ -17,8 +17,7 @@ val v :
   ([> `Built | `Checked ] Current_term.Output.t * Current.job_id option)
   Current.t
 (** Build and test all the opam packages in a given build context on the given
-    platform. [~repo] is the ID of the repository-under-test on a Git Forge
-    (e.g. GitHub or GitLab).
+    platform. [~repo] is the ID of the repository-under-test on GitHub.
 
     @param on_cancel The callback function to call if the job is cancelled.
     @param repo The ID of the repository-under-test on GitHub. *)

web-ui/static/images/gitlab-logo-500.png

@@ -25,9 +25,7 @@ module Make (M : Forge_prefix) = struct
         ())
 
   let logo =
-    match M.prefix with
-    | "github" -> Common.github_logo
-    | _ -> raise Not_found
+    match M.prefix with "github" -> Common.github_logo | _ -> raise Not_found
 
   let git_forge_url org = Printf.sprintf "https://%s.com/%s" M.prefix org
 

web-ui/static/images/index-page-search.png

@@ -6,9 +6,7 @@ module Make (M : Git_forge_intf.Forge) = struct
   type t = Branch of string | PR of { title : string; id : string }
 
   let logo =
-    match M.prefix with
-    | "github" -> Common.github_logo
-    | _ -> raise Not_found
+    match M.prefix with "github" -> Common.github_logo | _ -> raise Not_found
 
   let row ~ref ~short_hash ~started_at ~ran_for ~status ~ref_uri ~message =
     let ref_title =