[ExpressionLanguage] added some tests for the built-in constant() function
minor #10223 [ExpressionLanguage] added some tests for the built-in constant() function (fabpot)

This PR was merged into the 2.4 branch.

Discussion
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[ExpressionLanguage] added some tests for the built-in constant() function

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10216
| License       | MIT
| Doc PR        | n/a

Commits
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d8f55f5 [ExpressionLanguage] added some tests for the built-in constant() function