Enable release mode builds (#77)

### Motivation:

Some errors do not show up in debug builds. Enabling release mode builds
improves the CI coverage.

### Modifications:

Enable release mode builds for pull requests and scheduled builds on
main.

### Result:

Improved CI coverage.

Author: josephnoir

.github/workflows/main.yml

@@ -35,3 +35,12 @@ jobs:
     with:
       runner_pool: nightly
       build_scheme: swift-openapi-urlsession
+
+  release-builds:
+    name: Release builds
+    uses: apple/swift-nio/.github/workflows/release_builds.yml@main
+    with:
+      windows_6_0_enabled: true
+      windows_6_1_enabled: true
+      windows_nightly_next_enabled: true
+      windows_nightly_main_enabled: true

.github/workflows/pull_request.yml

@@ -43,3 +43,12 @@ jobs:
     with:
       runner_pool: general
       build_scheme: swift-openapi-urlsession
+
+  release-builds:
+    name: Release builds
+    uses: apple/swift-nio/.github/workflows/release_builds.yml@main
+    with:
+      windows_6_0_enabled: true
+      windows_6_1_enabled: true
+      windows_nightly_next_enabled: true
+      windows_nightly_main_enabled: true