Maybe this works

.travis.yml

@@ -15,14 +15,14 @@ php:
   - nightly
 
 env:
-  matrix:
-    - DEPS="high"
-    - DEPS="low"
   global:
     - DEFAULT_COMPOSER_FLAGS="--no-interaction --no-suggest --prefer-source"
     - XDEBUG="false"
     # generated with travis encrypt -r vimeo/psalm --org GITHUB_TOKEN="<secret oauth token>"
     - secure: 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
+  jobs:
+    - DEPS="high"
+    - DEPS="low"
 
 cache:
   directories:
@@ -48,10 +48,14 @@ script:
   - vendor/bin/phpunit
   - ./psalm
 
-jobs:
+# Base test matrix (php/env)
+matrix:
   fast_finish: true
   allow_failures:
     - php: nightly
+
+# Additional stages
+jobs:
   include:
     - stage: Code style analysis
       php: 7.3