Small documentation fix.

[schauder]

Created from a comment: #1856 (comment)

Hi, @mp911de!
Thank you for feature!
Please fix documentation file https://github.com/spring-projects/spring-data-relational/blob/main/spring-data-r2dbc/src/test/java/org/springframework/data/r2dbc/documentation/PersonRepository.java

Line @Query("SELECT * FROM #{tableName} WHERE lastname = :lastname")

Expression must be #{#tableName}