MINOR: [C#] Bump Google.Protobuf to 3.32.0 (#47364)

Updated [Google.Protobuf](https://github.com/protocolbuffers/protobuf) from 3.31.1 to 3.32.0.

<details>
<summary>Release notes</summary>

_Sourced from [Google.Protobuf's releases](https://github.com/protocolbuffers/protobuf/releases)._

No release notes found for this version range.

Commits viewable in [compare view](https://github.com/protocolbuffers/protobuf/commits).
</details>

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@ dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@ dependabot rebase` will rebase this PR
- `@ dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@ dependabot merge` will merge this PR after your CI passes on it
- `@ dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@ dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@ dependabot reopen` will reopen this PR if it is closed
- `@ dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@ dependabot show <dependency name> ignore conditions` will show all of the ignore conditions of the specified dependency
- `@ dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
- `@ dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
- `@ dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

</details>

Authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Signed-off-by: Curt Hagenlocher <[email protected]>

Author: dependabot[bot]

csharp/src/Apache.Arrow.Flight/Apache.Arrow.Flight.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.31.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.32.0" />
     <PackageReference Include="Grpc.Net.Client" Version="2.65.0" />
     <PackageReference Include="Grpc.Tools" Version="2.72.0" PrivateAssets="All" />
     <PackageReference Include="System.Memory" Version="4.6.0" />

csharp/test/Apache.Arrow.Flight.TestWeb/Apache.Arrow.Flight.TestWeb.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.31.1" />
+    <PackageReference Include="Google.Protobuf" Version="3.32.0" />
     <PackageReference Include="Grpc.AspNetCore" Version="2.71.0" />
   </ItemGroup>