tests: run python3 instead of python

tests/unit/builder-dockerfile.bats

@@ -152,7 +152,7 @@ EOF
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "dokku run $TEST_APP python task.py test"
+  run /bin/bash -c "dokku run $TEST_APP python3 task.py test"
   echo "output: $output"
   echo "status: $status"
   assert_success

tests/unit/builder-herokuish.bats

@@ -105,7 +105,7 @@ teardown() {
   echo "status: $status"
   assert_success
 
-  run /bin/bash -c "dokku run $TEST_APP python task.py test"
+  run /bin/bash -c "dokku run $TEST_APP python3 task.py test"
   echo "output: $output"
   echo "status: $status"
   assert_success

tests/unit/builder-nixpacks.bats

@@ -62,7 +62,7 @@ teardown() {
   assert_output_contains 'load build definition from Dockerfile' -1
   assert_output_contains "SECRET_KEY: fjdkslafjdk"
 
-  run /bin/bash -c "dokku run $TEST_APP python task.py test"
+  run /bin/bash -c "dokku run $TEST_APP python3 task.py test"
   echo "output: $output"
   echo "status: $status"
   assert_success

tests/unit/builder-pack.bats

@@ -95,7 +95,7 @@ teardown() {
   assert_output_contains 'Building with buildpack 1' 0
   assert_output_contains 'Installing dependencies using pip'
 
-  run /bin/bash -c "dokku run $TEST_APP python task.py test"
+  run /bin/bash -c "dokku run $TEST_APP python3 task.py test"
   echo "output: $output"
   echo "status: $status"
   assert_success

tests/unit/builder-railpack.bats

@@ -72,7 +72,7 @@ teardown() {
   assert_output_contains 'create mise config'
   assert_output_contains 'Successfully built image in'
 
-  run /bin/bash -c "dokku run $TEST_APP python task.py test"
+  run /bin/bash -c "dokku run $TEST_APP python3 task.py test"
   echo "output: $output"
   echo "status: $status"
   assert_success