Add Downgrade CI workflow (#582)

* Add Downgrade CI

* Relax `[compat]` package versions for std libs

https://discourse.julialang.org/t/psa-compat-requirements-in-the-general-registry-are-changing/104958

* Adjust `[compat]` package versions for `Requires`

---------

Co-authored-by: john verzani <jverzani@gmail.com>

Author: fhagemann

.github/workflows/Downgrade.yml

@@ -0,0 +1,28 @@
+name: Downgrade
+on:
+  pull_request:
+    branches:
+      - master
+    paths-ignore:
+      - 'docs/**'
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'docs/**'
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        version: ['1.6', '1']
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v1
+        with:
+          version: ${{ matrix.version }}
+      - uses: julia-actions/julia-downgrade-compat@v1
+        with:
+          skip: Pkg,TOML
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1

Project.toml

@@ -29,16 +29,16 @@ ChainRulesCore = "1"
 ChainRulesTestUtils = "1"
 DualNumbers = "0.6"
 FFTW = "1"
-LinearAlgebra = "1.6"
+LinearAlgebra = "<0.0.1, 1"
 MakieCore = "0.6,0.7, 0.8"
 MutableArithmetics = "1"
 OffsetArrays = "1"
 RecipesBase = "0.7, 0.8, 1"
-Requires = "1.0"
+Requires = "1.1"
 Setfield = "1"
-SparseArrays = "1.6"
+SparseArrays = "<0.0.1, 1"
 SpecialFunctions = "1,2"
-Test = "1.6"
+Test = "<0.0.1, 1"
 julia = "1.6"
 
 [extras]