ci(windows): set env vars using bash to populate GITHUB_ENV

Ensure wd_path/kit_path/KIT are written via bash so Windows gets proper KIT for build/test. Stabilizes overlay-helpers by guaranteeing KIT is defined.

Author: johnlindquist

.github/workflows/release.yml

@@ -22,6 +22,7 @@ jobs:
         uses: rlespinasse/github-slug-action@v4
 
       - name: Set env vars
+        shell: bash
         run: |
           echo "wd_path=$PWD" >> $GITHUB_ENV
           echo "kit_path=$PWD/.kit" >> $GITHUB_ENV
@@ -81,6 +82,7 @@ jobs:
         uses: rlespinasse/github-slug-action@v4
 
       - name: Set env vars
+        shell: bash
         run: |
           echo "wd_path=$PWD" >> $GITHUB_ENV
           echo "kit_path=$PWD/.kit" >> $GITHUB_ENV
@@ -120,6 +122,7 @@ jobs:
         uses: rlespinasse/github-slug-action@v4
 
       - name: Set env vars
+        shell: bash
         run: |
           echo "wd_path=$PWD" >> $GITHUB_ENV
           echo "kit_path=$PWD/.kit" >> $GITHUB_ENV