peg poetry version in CI

Author: bckohan

.github/workflows/test.yml

@@ -194,6 +194,7 @@ jobs:
       - name: Install Poetry
         uses: snok/install-poetry@v1
         with:
+          version: 1.5.1
           virtualenvs-create: true
           virtualenvs-in-project: true
       - name: Install Dependencies
@@ -260,6 +261,7 @@ jobs:
       - name: Install Poetry
         uses: snok/install-poetry@v1
         with:
+          version: 1.5.1
           virtualenvs-create: true
           virtualenvs-in-project: true
       - name: Install Dependencies
@@ -334,6 +336,7 @@ jobs:
       - name: Install Poetry
         uses: snok/install-poetry@v1
         with:
+          version: 1.5.1
           virtualenvs-create: true
           virtualenvs-in-project: true
       - name: Install Dependencies
@@ -404,6 +407,7 @@ jobs:
       - name: Install Poetry
         uses: snok/install-poetry@v1
         with:
+          version: 1.5.1
           virtualenvs-create: true
           virtualenvs-in-project: true
       - name: Install Oracle Client