Update `BeanRegistrationCodeFragments` package-private constructor to set `codeFragments` to `this` rather than `null`. The field is never actually read by `DefaultBeanRegistrationCodeFragments` since all methods are overridden. Closes gh-28578
Update `BeanRegistrationCodeFragments` package-private constructor to set `codeFragments` to `this` rather than `null`. The field is never actually read by `DefaultBeanRegistrationCodeFragments` since all methods are overridden. Closes gh-28578