build: remove uv dynamic versioning (#824)

It's not fully transparent for non-release versions (like alpha or rc)
how git tag names (i.e. `v1.0.0-alpha.0`) are converted to [Python
version
specifiers](https://packaging.python.org/en/latest/specifications/version-specifiers/#version-specifiers)
(i.e. `1.0.0a0`). This can be checked only during [publish GitHub
action](https://github.com/a2aproject/a2a-python/actions/workflows/python-publish.yml)
execution which both builds and pushes PyPi package.

`release-please` supports updating `pyproject.toml` so we will have the
same level of automation.

Current version is set to `0.3.25` - the latest release from `main`.

Author: ishymko

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "a2a-sdk"
-dynamic = ["version"]
+version = "0.3.25"
 description = "A2A Python SDK"
 readme = "README.md"
 license = "Apache-2.0"
@@ -62,7 +62,7 @@ changelog = "https://github.com/a2aproject/a2a-python/blob/main/CHANGELOG.md"
 documentation = "https://a2a-protocol.org/latest/sdk/python/"
 
 [build-system]
-requires = ["hatchling", "uv-dynamic-versioning", "hatch-build-scripts"]
+requires = ["hatchling", "hatch-build-scripts"]
 build-backend = "hatchling.build"
 
 [tool.hatch.build.hooks.build-scripts]
@@ -72,8 +72,6 @@ artifacts = ["src/a2a/types/a2a.json"]
 commands = ["bash scripts/gen_proto.sh"]
 work_dir = "."
 
-[tool.hatch.version]
-source = "uv-dynamic-versioning"
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/a2a"]
@@ -104,9 +102,6 @@ filterwarnings = [
 [tool.pytest-asyncio]
 mode = "strict"
 
-[tool.uv-dynamic-versioning]
-vcs = "git"
-style = "pep440"
 
 [dependency-groups]
 dev = [
@@ -119,7 +114,6 @@ dev = [
   "pytest-xdist>=3.6.1",
   "respx>=0.20.2",
   "ruff>=0.12.8",
-  "uv-dynamic-versioning>=0.8.2",
   "types-protobuf",
   "types-requests",
   "pre-commit",