fix: Bump MSRV to 1.56.0

This is needed for `Bound::cloned` and fits within official MSRV policy
(2 versions back) and unofficial (6 months, see clap-rs#3267)

.clippy.toml

@@ -1 +1 @@
-msrv = "1.54.0"  # MSRV
+msrv = "1.56.0"  # MSRV

.github/workflows/ci.yml

@@ -78,7 +78,7 @@ jobs:
         build: [msrv, wasm, wasm-wasi, debug, release]
         include:
           - build: msrv
-            rust: 1.54.0  # MSRV
+            rust: 1.56.0  # MSRV
             target: x86_64-unknown-linux-gnu
             features: full
           - build: wasm
@@ -122,7 +122,7 @@ jobs:
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
-        toolchain: 1.54.0  # MSRV
+        toolchain: 1.56.0  # MSRV
         profile: minimal
         override: true
     - uses: Swatinem/rust-cache@v1
@@ -172,7 +172,7 @@ jobs:
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
-        toolchain: 1.54.0  # MSRV
+        toolchain: 1.56.0  # MSRV
         profile: minimal
         override: true
         components: clippy

.github/workflows/rust-next.yml

@@ -92,9 +92,9 @@ jobs:
     strategy:
       matrix:
         rust:
-        - 1.54.0  # MSRV
+        - 1.56.0  # MSRV
         - stable
-    continue-on-error: ${{ matrix.rust != '1.54.0' }}  # MSRV
+    continue-on-error: ${{ matrix.rust != '1.56.0' }}  # MSRV
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository

Cargo.toml

@@ -10,6 +10,7 @@ members = [
 [package]
 name = "clap"
 version = "3.1.18"
+rust-version = "1.56.0"  # MSRV
 description = "A simple to use, efficient, and full-featured Command Line Argument Parser"
 repository = "https://github.com/clap-rs/clap"
 documentation = "https://docs.rs/clap/"

Makefile

@@ -10,7 +10,7 @@ ifneq (${TOOLCHAIN_TARGET},)
   ARGS+=--target ${TOOLCHAIN_TARGET}
 endif
 
-MSRV?=1.54.0
+MSRV?=1.56.0
 
 _FEATURES = minimal default wasm full debug release
 _FEATURES_minimal = --no-default-features --features "std"

README.md

@@ -93,7 +93,7 @@ OPTIONS:
   - Leverage feature flags to keep to one active branch
   - Being under [WG-CLI](https://github.com/rust-cli/team/) to increase the bus factor
 - We follow semver and will wait about 6-9 months between major breaking changes
-- We will support the last two minor Rust releases (MSRV, currently 1.54.0)
+- We will support the last two minor Rust releases (MSRV, currently 1.56.0)
 
 While these aspirations can be at odds with fast build times and low binary
 size, we will still strive to keep these reasonable for the flexibility you