Fix CI on generated-enum

Generated enum files include `json.hpp' which causes the CI failures
like
```
/var/jenkins-openbmc/workspace/ci-repository/openbmc/bmcweb/redfish-core/include/generated/enums/acceleration_function.hpp:4:1: error: included header json.hpp is not used directly [misc-include-cleaner,-warnings-as-errors]
    4 | #include <nlohmann/json.hpp>
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
    5 |
```

So, this will treat  `<nlohmann/json.hpp>` as `misc-include-cleaner` to
ignore the header check.

Tested:
- Compiles good
- CI passes

Change-Id: Id1d5e981b1de37398aa02c3303357e66fe902efd
Signed-off-by: Myung Bae <myungbae@us.ibm.com>
diff --git a/.clang-tidy b/.clang-tidy
index ca5c0b3..479c65b 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -398,4 +398,4 @@
   - { key: readability-identifier-naming.StructIgnoredRegexp,  value: (BMCWEB_LOG_DEBUG|BMCWEB_LOG_INFO|BMCWEB_LOG_WARNING|BMCWEB_LOG_ERROR|BMCWEB_LOG_CRITICAL) }
   - { key: cppcoreguidelines-macro-usage.AllowedRegexp, value: DEBUG*|NLOHMANN_JSON_SERIALIZE_ENUM }
   - { key: cppcoreguidelines-rvalue-reference-param-not-moved.IgnoreUnnamedParams, value: true }
-  - { key: misc-include-cleaner.IgnoreHeaders, value: ((nlohmann/json_fwd.hpp)|(boost/asio/connect_pipe.hpp)|(boost/beast/websocket/rfc6455.hpp)|(read.hpp)|(write.hpp)|(boost/circular_buffer.hpp)|(boost/asio/.*read.hpp)|(boost/.*/src.hpp)|(boost/.*/detail/.*)|(nlohmann/detail/.*)|(stdio.h)|(ranges)|(bits/.*)|(boost/system/error_code.hpp)|(json_formatters.hpp)|(boost_formatters.hpp)|(CLI/.*)) }
+  - { key: misc-include-cleaner.IgnoreHeaders, value: ((nlohmann/json.hpp)|(nlohmann/json_fwd.hpp)|(boost/asio/connect_pipe.hpp)|(boost/beast/websocket/rfc6455.hpp)|(read.hpp)|(write.hpp)|(boost/circular_buffer.hpp)|(boost/asio/.*read.hpp)|(boost/.*/src.hpp)|(boost/.*/detail/.*)|(nlohmann/detail/.*)|(stdio.h)|(ranges)|(bits/.*)|(boost/system/error_code.hpp)|(json_formatters.hpp)|(boost_formatters.hpp)|(CLI/.*)) }