Update CI jobs to test newer Asio versions

Update the unittests to test against the currently newest release of
boost and asio.

.github/workflows/unittest.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        boost_version: ["1.81.0", "1.82.0", "1.83.0", "1.84.0"]
+        boost_version: ["1.83.0", "1.84.0", "1.85.0", "1.86.0"]
         os: [windows-2019, windows-2022]
         toolset: [v142, v143, ClangCL]
         build_type: [Debug, Release]
@@ -155,7 +155,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        asio_version: ["asio-1-28-0", "asio-1-29-0"]
+        asio_version: ["asio-1-31-0", "asio-1-32-0"]
         os: [windows-2022]
         build_type: [Debug, Release]
         standard: [14, 17, 20]

README.md

@@ -44,7 +44,7 @@ Code using this library must target at least
 
 Either [Asio](https://think-async.com/Asio/) or the [Boost
 libraries](https://www.boost.org) are required. Currently tested with
-Boost 1.81 to 1.84 and Asio 1.28 to 1.29 but at least most newer
+Boost 1.83 to 1.86 and Asio 1.31 to 1.32 but at least most newer
 versions ought to work.
 
 A working C++ compiler supporting at least the C++14 standard is