Follow-up from issue

• Drop support in checks for no-longer-compilable preview feature - Pattern matching for swtich #18104

JEP 406 introduced a new preview feature in Java 17 called Pattern Matching for switch. Checkstyle added support for this in Issue #10848 and PR #11100. Since then, however, the feature got refined multiple times in:

• JEP 420: Pattern Matching for switch (Second Preview)
• JEP 427: Pattern Matching for switch (Third Preview)
• JEP 433: Pattern Matching for switch (Fourth Preview)

In those refinements, some syntax was dropped and it is no longer compilable with Java 21. Checkstyle still supports this outdated grammar.

The goal of this issue is to remove ANTLR grammar for Pattern Matching for switch. The grammar was added in PR

• Issue #10848: Support patterns in switch #11100