CI: Record one result with duration (#57954)

Helps fill this out with something meaningful, which is better than the
current zero duration and the old overcounting.


https://buildkite.com/organizations/julialang/analytics/suites/julialang-base?branch=master

<img width="1046" alt="Screenshot 2025-03-30 at 11 19 20 PM"
src="https://github.com/user-attachments/assets/76e25e2d-aef8-4687-b349-c7017a7b3cdd"
/>

Author: IanButterworth

test/buildkitetestjson.jl

@@ -258,9 +258,16 @@ function serialize_testset_result_file(dir::String, testset::Test.DefaultTestSet
 end
 
 # deserilalizes the results files and writes them to collated JSON files of 5000 max results
-function write_testset_json_files(dir::String)
+function write_testset_json_files(dir::String, testset::Test.DefaultTestSet)
     data = Dict{String,Any}[]
     read_files = String[]
+    # Set one result to represent the overall duration, given results have no duration
+    overall_ts = result_dict(testset)
+    # don't set location or file name for this result. They aren't required by BK
+    overall_ts["result"] = "unknown"
+    overall_ts["name"] = replace(get(ENV, "BUILDKITE_LABEL", "job label not found"), r":\w+:\s*" => "")
+    push!(data, overall_ts)
+    # Load all the serialized results files
     for res_dat in filter!(x -> occursin(r"^results.*\.dat$", x), readdir(dir))
         res_file = joinpath(dir, res_dat)
         append!(data, Serialization.deserialize(res_file))

test/runtests.jl

@@ -342,8 +342,6 @@ cd(@__DIR__) do
         end
     end
 
-    BuildkiteTestJSON.write_testset_json_files(@__DIR__)
-
     #=
 `   Construct a testset on the master node which will hold results from all the
     test files run on workers and on node1. The loop goes through the results,
@@ -369,6 +367,7 @@ cd(@__DIR__) do
     Test.TESTSET_PRINT_ENABLE[] = false
     o_ts = Test.DefaultTestSet("Overall")
     o_ts.time_end = o_ts.time_start + o_ts_duration # manually populate the timing
+    BuildkiteTestJSON.write_testset_json_files(@__DIR__, o_ts)
     Test.push_testset(o_ts)
     completed_tests = Set{String}()
     for (testname, (resp,), duration) in results