[Bug]: docker build fails on compile step

### What happened?

`docker build --progress=plain -t a2a-inspector . > build.log 2>&1`

[build.log](https://github.com/user-attachments/files/22936640/build.log)

### Relevant log output

```shell
-- SNIP -- (See log file for full details)
#21 5.964 -c src/c/_cffi_backend.c -o
#21 5.964 build/temp.linux-x86_64-cpython-314/src/c/_cffi_backend.o
#21 5.964
#21 5.964 [stderr]
#21 5.964
#21 5.964 No working compiler found, or bogus compiler options passed to
#21 5.964 the compiler from Python's standard "distutils" module. See
#21 5.964 the error messages above. Likely, the problem is not related
#21 5.964 to CFFI but generic to the setup.py of any Python package that
#21 5.964 tries to compile C code. (Hints: on OS/X 10.8, for errors about
#21 5.964 -mno-fused-madd see http://stackoverflow.com/questions/22313407/
#21 5.964 Otherwise, see https://wiki.python.org/moin/CompLangPython or
#21 5.964 the IRC channel #python on irc.libera.chat.)
#21 5.964
#21 5.964 Trying to continue anyway. If you are trying to install CFFI from
#21 5.964 a build done in a different context, you can ignore this warning.
#21 5.964
#21 5.964 /tmp/.tmpwCXAyb/builds-v0/.tmpxIuwIS/lib/python3.14/site-packages/setuptools/dist.py:759:
#21 5.964 SetuptoolsDeprecationWarning: License classifiers are deprecated.
#21 5.964 !!
#21 5.964
#21 5.964
#21 5.964 ********************************************************************************
#21 5.964 Please consider removing the following classifiers in favor of a
#21 5.964 SPDX license expression:
#21 5.964
#21 5.964 License :: OSI Approved :: MIT License
#21 5.964
#21 5.964 See
#21 5.964 https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license
#21 5.964 for details.
#21 5.964
#21 5.964 ********************************************************************************
#21 5.964
#21 5.964 !!
#21 5.964 self._finalize_license_expression()
#21 5.964 error: command 'cc' failed: No such file or directory
#21 5.964
#21 5.964 hint: This usually indicates a problem with the package or the build
#21 5.964 environment.
#21 5.964 help: `cffi` (v1.17.1) was included because `a2a-inspector-workspace`
#21 5.964 (v0.1.0) depends on `jwcrypto` (v1.5.6) which depends on
#21 5.964 `cryptography` (v45.0.4) which depends on `cffi`
#21 ERROR: process "/bin/sh -c uv sync --no-cache" did not complete successfully: exit code: 1
------
> [stage-1 5/10] RUN uv sync --no-cache:
5.964
5.964 !!
5.964 self._finalize_license_expression()
5.964 error: command 'cc' failed: No such file or directory
5.964
5.964 hint: This usually indicates a problem with the package or the build
5.964 environment.
5.964 help: `cffi` (v1.17.1) was included because `a2a-inspector-workspace`
5.964 (v0.1.0) depends on `jwcrypto` (v1.5.6) which depends on
5.964 `cryptography` (v45.0.4) which depends on `cffi`
------
Dockerfile:27
--------------------
25 | RUN pip install uv
26 | COPY pyproject.toml uv.lock ./
27 | >>> RUN uv sync --no-cache
28 | RUN uv pip install validators
29 | COPY backend/ ./backend/
--------------------
ERROR: failed to build: failed to solve: process "/bin/sh -c uv sync --no-cache" did not complete successfully: exit code: 1
```

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct