chore: update msrv to 1.68 (#3094)

.github/workflows/bench.yml

@@ -2,8 +2,7 @@ name: Benchmark
 
 on:
   push:
-    branches:
-      - master
+    branches: [master]
 
 permissions:
   contents: read # to fetch code (actions/checkout)

.github/workflows/ci.yml

@@ -3,6 +3,8 @@ name: CI
 on:
   pull_request:
     types: [opened, synchronize, reopened]
+  merge_group:
+    types: [checks_requested]
   push:
     branches: [master]
 
@@ -24,7 +26,7 @@ jobs:
           - { name: macOS, os: macos-latest, triple: x86_64-apple-darwin }
           - { name: Windows, os: windows-latest, triple: x86_64-pc-windows-msvc }
         version:
-          - 1.65.0 # MSRV
+          - 1.68.0 # MSRV
           - stable
 
     name: ${{ matrix.target.name }} / ${{ matrix.version }}