Spring Fix invalid characters in source files

From the main build on JDK 17:

> Task :spring-beans:compileGroovy
/tmp/build/6da1d659/git-repo/spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java:355: error: unmappable character (0xC2) for encoding US-ASCII
                        throw new IllegalStateException("No scope name defined for bean ??" + beanName + "'");
                                                                                        ^
/tmp/build/6da1d659/git-repo/spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java:355: error: unmappable character (0xB4) for encoding US-ASCII
                        throw new IllegalStateException("No scope name defined for bean ??" + beanName + "'");
                                                                                         ^

> Task :spring-expression:javadoc
/tmp/build/6da1d659/git-repo/spring-expression/src/main/java/org/springframework/expression/spel/ast/BeanReference.java:29: warning: invalid input: '&foo'
 * For a FactoryBean the syntax <tt>&foo</tt> can be used to access the factory itself.
                                    ^
/tmp/build/6da1d659/git-repo/spring-expression/src/main/java/org/springframework/expression/BeanResolver.java:22: warning: invalid input: '&'
 * The <tt>&</tt> variant syntax allows access to the factory bean where relevant.
           ^
/tmp/build/6da1d659/git-repo/spring-expression/src/main/java/org/springframework/expression/BeanResolver.java:31: warning: invalid input: '&'
     * For attempting access to a factory bean, the name needs a <tt>&</tt> prefix.
                                                                     ^

> Task :spring-expression:javadoc
/tmp/build/6da1d659/git-repo/spring-expression/src/main/java/org/springframework/expression/TypeComparator.java:43: warning: invalid input: '<'
     * @return 0 if they are equal, <0 if the first is smaller than the second,
                                    ^
/tmp/build/6da1d659/git-repo/spring-expression/src/main/java/org/springframework/expression/TypeComparator.java:43: warning: invalid input: '<'
     * @return 0 if they are equal, <0 if the first is smaller than the second,
                                    ^