NullAway 0.12.7

• Update to Checker Framework 3.49.2 (#1183)
• Don't check synchronized blocks within unannotated code (#1185)
• Test on JDK 24 (#1187)
• Fix multiple issues with NewClassTrees that have enclosing expressions (#1191)
• Ensure classes null-marked by library model detected in all places (#1197)
• JSpecify: handle varargs whose element type is a type variable (#1200)
• Update to Error Prone 2.38.0 (#1203)
• Optimization to annotation stripping in library model matching (#1204)
• Make arg position nullness array contents nullable (#1207)
• Properly handle method references to null-unmarked methods (#1205)