release: bump 0.8.2 -> 0.8.3 (#249)

Version bump 0.8.2 → 0.8.3, releasing the per-binding throughput benchmark work
(merged in #246).

Bumped via `ScriptHelpers/bump_version.py` across all manual touchpoints —
`Cargo.toml`, `pyproject.toml`, the Node `package.json` + 6 platform packages +
both lockfiles, the Java `pom.xml`s + README, the C# `.csproj`, the R
`DESCRIPTION` — plus `Cargo.lock` (via `cargo build`) and the `CHANGELOG.md`
`[0.8.3]` section and compare URLs.

CHANGELOG `[0.8.3]`:
- Per-binding throughput benchmarks for all 9 targets (BENCHMARKS.md §3).
- C ABI archetype test (`examples/c/archetypes.c`).

`cargo fmt`, `cargo test --workspace --all-features` (all green) and
`cargo clippy --workspace --all-targets --all-features -D warnings` pass. The
docs/webpage version strings are bumped by `sync-about.yml` on the `v*` tag —
not touched here.

examples/java/pom.xml

@@ -6,7 +6,7 @@
 
   <groupId>org.wickra.examples</groupId>
   <artifactId>wickra-examples</artifactId>
-  <version>0.8.2</version>
+  <version>0.8.3</version>
   <packaging>jar</packaging>
 
   <name>Wickra Java examples</name>
@@ -21,7 +21,7 @@
     <dependency>
       <groupId>org.wickra</groupId>
       <artifactId>wickra</artifactId>
-      <version>0.8.2</version>
+      <version>0.8.3</version>
     </dependency>
     <!-- Only the network examples (fetch_btcusdt) parse JSON. -->
     <dependency>