Enable Sendability checks on CI

> **Note**: merge swift-server#31 first to make CI pass

Author: felixschlegel

Diff for: docker/docker-compose.2204.57.yaml

@@ -13,6 +13,7 @@ services:
     image: swift-memcache-gsoc:22.04-5.7
     environment:
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
+      - STRICT_CONCURRENCY_ARG=-Xswiftc -strict-concurrency=complete
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still
 
   shell:

Diff for: docker/docker-compose.2204.58.yaml

@@ -14,6 +14,7 @@ services:
     environment:
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
       - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
+      - STRICT_CONCURRENCY_ARG=-Xswiftc -strict-concurrency=complete
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still
 
   shell:

Diff for: docker/docker-compose.2204.59.yaml

@@ -13,6 +13,7 @@ services:
     environment:
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
       - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
+      - STRICT_CONCURRENCY_ARG=-Xswiftc -strict-concurrency=complete
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still
 
   shell:

Diff for: docker/docker-compose.2204.main.yaml

@@ -13,6 +13,7 @@ services:
     environment:
       - WARN_AS_ERROR_ARG=-Xswiftc -warnings-as-errors
       - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
+      - STRICT_CONCURRENCY_ARG=-Xswiftc -strict-concurrency=complete
       # - SANITIZER_ARG=--sanitize=thread # TSan broken still
 
   shell:

Diff for: docker/docker-compose.yaml

@@ -3,12 +3,12 @@ version: "3.9"
 services:
   # Swift on Server CI
   # e.g. docker-compose -f docker/docker-compose.yaml -f docker/docker-compose.2204.57.yaml run test
-  
+
   memcached:
     image: memcached:latest
     ports:
         - "11211:11211"
-  
+
   runtime-setup:
     image: swift-memcache-gsoc:default
     build:
@@ -32,7 +32,7 @@ services:
     depends_on:
         - runtime-setup
         - memcached
-    command: /bin/bash -xcl "swift $${SWIFT_TEST_VERB-test} $${WARN_AS_ERROR_ARG-} $${SANITIZER_ARG-} $${IMPORT_CHECK_ARG-}"
+    command: /bin/bash -xcl "swift $${SWIFT_TEST_VERB-test} $${WARN_AS_ERROR_ARG-} $${SANITIZER_ARG-} $${IMPORT_CHECK_ARG-} $${STRICT_CONCURRENCY_ARG-}"
 
   # util