Split lint, unit test jobs

There's no reason we need to constrain our version of Go for linters:
It is only necessary for unit tests. Make this possible by splitting our
workflows.

Signed-off-by: Stephen Finucane <[email protected]>

Author: stephenfin

.github/workflows/lint.yaml

@@ -0,0 +1,20 @@
+name: Unit Testing
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+
+    steps:
+      - name: Checkout source
+        uses: actions/checkout@v5
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.25"
+
+      - name: Run linters
+        run: |
+          make lint

.github/workflows/unit.yml

@@ -3,24 +3,14 @@ on: [push, pull_request]
 jobs:
   test:
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        go-version:
-          - "1.22"
-
     steps:
       - name: Checkout source
         uses: actions/checkout@v5
 
-      - name: Setup Go ${{ matrix.go-version }}
+      - name: Setup Go
         uses: actions/setup-go@v5
         with:
-          go-version: ${{ matrix.go-version }}
-
-      - name: Run linters
-        run: |
-          make lint
+          go-version-file: 'go.mod'
 
       - name: Run unit tests
         run: |