Bump govuk_app_config from 8.1.1 to 9.0.3 #1694

Job	Run time
Test Ruby	1m 5s
Lint JavaScript / Run Standardx	17s
Lint Ruby / Run RuboCop	21s
Lint SCSS / Run Stylelint	14s
Security Analysis / Run Brakeman	20s
Test JavaScript / Run Jasmine	1m 10s
	3m 27s

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