Bump com.github.johnrengelman.shadow (#360)

Bumps com.github.johnrengelman.shadow from 5.1.0 to 8.1.1.

---
updated-dependencies:
- dependency-name: com.github.johnrengelman.shadow
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

samples/lambda-kotlin-request-router-sample/build.gradle.kts

@@ -16,7 +16,7 @@ plugins {
     java
     kotlin("jvm") version "1.3.50"
     idea
-    id("com.github.johnrengelman.shadow") version "5.1.0"
+    id("com.github.johnrengelman.shadow") version "8.1.1"
     id("org.jmailen.kotlinter") version "4.3.0"
 }