Update min Swift version to 5.6 and make platform versions consistent (#103)

Update minimum Swift version to 5.6 and make platform versions consistent.

Author: gwynne

.github/workflows/test.yml

@@ -1,4 +1,7 @@
 name: test
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 on:
   pull_request: { branches: ['*'] }
   push: { branches: [ main ] }
@@ -20,7 +23,7 @@ jobs:
   dependents-check:
     if: github.event_name == 'pull_request'
     runs-on: ubuntu-latest
-    container: swift:5.7-jammy
+    container: swift:5.8-jammy
     steps:
       - name: Check out package
         uses: actions/checkout@v3

Package.swift

@@ -1,11 +1,13 @@
-// swift-tools-version:5.5
+// swift-tools-version:5.6
 import PackageDescription
 
 let package = Package(
     name: "sqlite-kit",
     platforms: [
         .macOS(.v10_15),
-        .iOS(.v13)
+        .iOS(.v13),
+        .watchOS(.v6),
+        .tvOS(.v13),
     ],
     products: [
         .library(name: "SQLiteKit", targets: ["SQLiteKit"]),