Switch continuous-integration workflow to build from main

  This will be necessary until we have released a version supporting 'bench' & al the machinery behind it.

Signed-off-by: KtorZ <[email protected]>

Author: KtorZ

.github/workflows/continuous-integration.yml

@@ -10,9 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - uses: aiken-lang/setup-aiken@v1
-        with:
-          version: v1.1.9
+      - run: cargo install --verbose --git https://github.com/aiken-lang/aiken.git
       - run: aiken fmt --check
       - run: aiken check -D
       - run: aiken build