Update scala-library to 2.12.20

Author: http4s-steward[bot]

.github/workflows/ci.yml

@@ -29,12 +29,12 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        scala: [2.12.17, 3.3.0, 2.13.10]
+        scala: [2.12.20, 3.3.0, 2.13.10]
         java: [temurin@8, temurin@11]
         project: [rootJS, rootJVM, rootNative]
         sjsStage: [FastOptStage, FullOptStage]
         exclude:
-          - scala: 2.12.17
+          - scala: 2.12.20
             java: temurin@11
           - scala: 3.3.0
             java: temurin@11

build.sbt

@@ -3,7 +3,7 @@ ThisBuild / startYear := Some(2022)
 ThisBuild / developers += tlGitHubDev("armanbilge", "Arman Bilge")
 ThisBuild / tlVersionIntroduced := List("2.12", "2.13", "3").map(_ -> "1.0.3").toMap
 
-ThisBuild / crossScalaVersions := Seq("2.12.17", "3.3.0", "2.13.10")
+ThisBuild / crossScalaVersions := Seq("2.12.20", "3.3.0", "2.13.10")
 
 ThisBuild / tlFatalWarningsInCi := false