Bump jackson-core from 2.10.3 to 2.12.2 (#343)

Bumps [jackson-core](https://github.com/FasterXML/jackson-core) from 2.10.3 to 2.12.2.
- [Release notes](https://github.com/FasterXML/jackson-core/releases)
- [Commits](FasterXML/jackson-core@jackson-core-2.10.3...jackson-core-2.12.2)

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

protocol/build.gradle.kts

@@ -46,7 +46,7 @@ kotlin {
                 implementation("junit:junit:4.13.2")
                 implementation(project(":protocol"))
                 //todo: shouldn't be 2.10.3
-                implementation("com.fasterxml.jackson.core:jackson-core:2.10.3")
+                implementation("com.fasterxml.jackson.core:jackson-core:2.12.2")
                 implementation("com.fasterxml.jackson.core:jackson-databind:2.10.3")
                 implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:2.12.2")
                 implementation("com.fasterxml.jackson.datatype:jackson-datatype-jdk8:2.12.2")