Update gsoc-2024.md to strikethrough unaccepted projects

programs/mentoring/gsoc/gsoc-2024.md

@@ -23,16 +23,16 @@ JSON Schema will be applying to 2024's Google Summer of Code Program as a mentor
 
 ## [Project Ideas](https://github.com/json-schema-org/community/issues?q=is%3Aopen+label%3Agsoc+sort%3Acreated-desc)
 Here is the list of our 2024 project ideas:
-- [#609](https://github.com/json-schema-org/community/issues/609): **New Bowtie Test Case Widgets**
 - [#607](https://github.com/json-schema-org/community/issues/607): **`bowtie-trend`: Long-Term Reporting With Bowtie**
-- [#606](https://github.com/json-schema-org/community/issues/606): **jsonschema.lean -- an implementation of JSON Schema in Lean**
 - [#605](https://github.com/json-schema-org/community/issues/605): **`bowtie-perf`: a Performance Tester for JSON Schema implementations**
 - [#603](https://github.com/json-schema-org/community/issues/603): **Setting up the CI/CD Pipeline for the JSON Schema website**
 - [#602](https://github.com/json-schema-org/community/issues/602): **Build a new version of the JSON Schema tooling page**
 - [#601](https://github.com/json-schema-org/community/issues/601): **JSON Schema Language Server Contributions**
 - [#599](https://github.com/json-schema-org/community/issues/599): **Define upgrade/downgrade language agnostic declarative transformation rules for all JSON Schema dialects**
 - [#614](https://github.com/json-schema-org/community/issues/614): **Source Generation Analyzer Powered by Corvus.JsonSchema (.Net)**
 - [#645](https://github.com/json-schema-org/community/issues/645): **A tour of JSON Schema**
+- ~~[#609](https://github.com/json-schema-org/community/issues/609): **New Bowtie Test Case Widgets**~~
+- ~~[#606](https://github.com/json-schema-org/community/issues/606): **jsonschema.lean -- an implementation of JSON Schema in Lean**~~
 
 ## Why choosing a JSON Schema project?