git: add clangd files to .gitignore (#4299)
git: add clangd files to .gitignore (#4299)

.cache/ and compile_commands.json are used by clangd for code
completion and should be ignored.

Signed-off-by: Emma Haruka Iwao <2e1cbee671064ab29b34254786a03b529fd96c06@google.com>
fluent/fluent-bit,fluent/fluent-bit,fluent/fluent-bit,nokute78/fluent-bit,fluent/fluent-bit,fluent/fluent-bit,fluent/fluent-bit,fluent/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,fluent/fluent-bit,nokute78/fluent-bit,fluent/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,fluent/fluent-bit,nokute78/fluent-bit,nokute78/fluent-bit,fluent/fluent-bit,fluent/fluent-bit