chore: manual acceptance test job

In order to trigger acceptance tests for certain branches pre-merge, and
without having to wait for a nightly build, you can click "trigger
pipeline" in CircleCI and enter `ACC_TESTS=1` as a parameter.

.circleci/config.yml

@@ -237,6 +237,22 @@ workflows:
             branches:
               only:
                 - main
+  manual-acc-tests:
+    when:
+      equal: ['1', << pipeline.parameters.ACC_TESTS >>]
+    jobs:
+      - test_acc:
+          name: "Acceptance tests: << matrix.pattern >>"
+          matrix:
+            parameters:
+              pattern:
+                - TestAcc_Aws
+                - TestAcc_Github_
+                - TestAcc_Google
+                - TestAcc_Azure_
+                - TestAcc_StateReader_
+          context:
+            - driftctl-acc
   pullrequest:
     jobs:
       - lint: