Revert "Teporarily bound Julia version for docs building"

This reverts commit 725be3c.

Author: andreasnoack

.github/workflows/ci.yml

@@ -52,7 +52,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: julia-actions/setup-julia@v1
         with:
-          version: '1.6.1'
+          version: '1'
       - run: |
           julia --project=docs -e '
             using Pkg
@@ -67,4 +67,4 @@ jobs:
       - run: julia --project=docs docs/make.jl
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }}
+          DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }}