deps: add ngtcp2_fmt.c to build configuration (ngtcp2.gyp)

[ShenHongFei]

The following compilation configuration will result in an error.

python configure.py --v8-enable-temporal-support --experimental-quic --experimental-dtls --enable-thin-lto --dest-cpu=x64 --clang-cl=20.1.8

lld-link : warning : ignoring unknown argument '-fno-lto' [D:\1\nodejs\node_mksnapshot.vcxproj]
lld-link : warning : ignoring unknown argument '-flto=thin' [D:\1\nodejs\node_mksnapshot.vcxproj]
lld-link : error : undefined symbol: ngtcp2_fmt_write_str [D:\1\nodejs\node_mksnapshot.vcxproj]
  >>> referenced by ngtcp2\lib\ngtcp2_conn.c
  >>>               ngtcp2.lib(ngtcp2_conn.obj)
  >>> referenced by ngtcp2\lib\ngtcp2_pv.c
  >>>               ngtcp2.lib(ngtcp2_pv.obj)
  >>> referenced by ngtcp2\lib\ngtcp2_log.c
  >>>               ngtcp2.lib(ngtcp2_log.obj)
  >>> referenced 3 more times
  
lld-link : error : undefined symbol: ngtcp2_fmt_write_uint64w [D:\1\nodejs\node_mksnapshot.vcxproj]
  >>> referenced by ngtcp2\lib\ngtcp2_conn.c
  >>>               ngtcp2.lib(ngtcp2_conn.obj)
  >>> referenced by ngtcp2\lib\ngtcp2_pv.c
  >>>               ngtcp2.lib(ngtcp2_pv.obj)
  >>> referenced by ngtcp2\lib\ngtcp2_log.c
  >>>               ngtcp2.lib(ngtcp2_log.obj)
  >>> referenced 3 more times
  
...

After investigation, it was found that the sources section of the ngtcp2.gyp configuration file was missing the ngtcp2_fmt.c file, which caused the linking failure. After adding it, local compilation could be done normally.

[nodejs-github-bot]

Review requested:

• @nodejs/gyp
• @nodejs/quic
• @nodejs/security-wg

[ShenHongFei]

#63777

This PR has added this file.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/74004/