Merge the 2 Cygwin workflows into 1 workflow with 2 jobs

Use "needs:" to ensure they are sequentially (to reuse the compiler
built in the first part for the second) and still having a full 6 hours
timeout each
"always()" ensures that "part2" runs even if a test failed in "part1"

Author: shym

.github/workflows/cygwin-510-trunk-workflow.yml

@@ -0,0 +1,26 @@
+name: Cygwin trunk
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  part1:
+    uses: ./.github/workflows/common.yml
+    with:
+      runs_on: windows-latest
+      compiler: ocaml.5.1.0
+      cygwin: true
+      compiler_git_ref: refs/heads/trunk
+      timeout: 360
+      subsuite: src/array src/atomic src/bigarray src/buffer src/bytes src/domain src/dynlink src/ephemeron src/floatarray src/hashtbl src/io
+
+  part2:
+    needs: part1
+    if: ${{ always() }}
+    uses: ./.github/workflows/common.yml
+    with:
+      runs_on: windows-latest
+      compiler: ocaml.5.1.0
+      cygwin: true
+      compiler_git_ref: refs/heads/trunk
+      timeout: 360
+      subsuite: src/lazy src/neg_tests src/queue src/semaphore src/stack src/statistics src/sys src/thread src/threadomain src/weak

.github/workflows/cygwin1-510-trunk-workflow.yml

@@ -16,9 +16,7 @@ Multicore tests
 [![Linux 32-bit 5.1.0+trunk](https://github.com/ocaml-multicore/multicoretests/actions/workflows/linux-510-32bit-trunk-workflow.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/linux-510-32bit-trunk-workflow.yml)
 [![Windows 5.1.0+trunk](https://github.com/ocaml-multicore/multicoretests/actions/workflows/windows-510-trunk-workflow.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/windows-510-trunk-workflow.yml)
 [![Windows 5.1.0+trunk-bytecode](https://github.com/ocaml-multicore/multicoretests/actions/workflows/windows-510-trunk-bytecode-workflow.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/windows-510-trunk-bytecode-workflow.yml)
-
-[![Cygwin trunk (1)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin1-510-trunk-workflow.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin1-510-trunk-workflow.yml)
-[![Cygwin trunk (2)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin2-510-trunk-workflow.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin2-510-trunk-workflow.yml)
+[![Cygwin 5.1.0+trunk](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin-510-trunk-workflow.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin-510-trunk-workflow.yml)
 
 Property-based tests of (parts of) the OCaml multicore compiler and run time.