Canonical CI: grouped-tests.yml + root test/test_groups.toml (#604)

Convert the root test workflow (Tests.yml) to the canonical thin caller of
SciML/.github/.github/workflows/grouped-tests.yml@v1, with the group x version
matrix declared once in test/test_groups.toml at the repo root.

The previous Tests.yml hand-maintained a version x group matrix (versions
1/lts/pre x groups InterfaceI/InterfaceII/QA, excluding pre+QA) calling
tests.yml@v1. That exact 8-cell matrix is now reproduced by test_groups.toml:
InterfaceI and InterfaceII on [lts, 1, pre], QA on [lts, 1].

runtests.jl already dispatches on the standard GROUP env var and already has a
QA group, so no runtests.jl change is needed and no with: inputs are required
(check-bounds, coverage, coverage-directories=src,ext, group-env-name=GROUP all
match the grouped-tests.yml@v1 defaults). on: triggers and concurrency: are
preserved verbatim; name: "Run Tests" is kept so branch-protection status
checks are unaffected. All other workflow files are left untouched.

Co-authored-by: ChrisRackauckas-Claude <accounts@chrisrackauckas.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: 3 people

.github/workflows/Tests.yml

@@ -18,23 +18,5 @@ concurrency:
 
 jobs:
   tests:
-    name: "Tests"
-    strategy:
-      fail-fast: false
-      matrix:
-        version:
-          - "1"
-          - "lts"
-          - "pre"
-        group:
-          - InterfaceI
-          - InterfaceII
-          - QA
-        exclude:
-          - version: "pre"
-            group: QA
-    uses: "SciML/.github/.github/workflows/tests.yml@v1"
-    with:
-      julia-version: "${{ matrix.version }}"
-      group: ${{ matrix.group }}
+    uses: "SciML/.github/.github/workflows/grouped-tests.yml@v1"
     secrets: "inherit"

test/test_groups.toml

@@ -0,0 +1,8 @@
+[InterfaceI]
+versions = ["lts", "1", "pre"]
+
+[InterfaceII]
+versions = ["lts", "1", "pre"]
+
+[QA]
+versions = ["lts", "1"]