Update CI to cater to new MSRV in b64-ct

.github/workflows/ci.yml

@@ -44,7 +44,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [beta, 1.65.0, 1.56.1]
+        rust: [beta, 1.79.0]
         os: [ubuntu]
         include:
           - rust: stable
@@ -68,9 +68,7 @@ jobs:
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,arbitrary_precision
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,raw_value
       - run: cargo check --manifest-path tests/crate/Cargo.toml --features serde_json/preserve_order
-        if: matrix.rust != '1.56.1'
       - run: cargo check --manifest-path tests/crate/Cargo.toml --no-default-features --features alloc,serde_json/preserve_order
-        if: matrix.rust != '1.56.1'
       - name: Build without std
         run: cargo check --manifest-path tests/crate/Cargo.toml --target ${{matrix.target}} --no-default-features --features alloc
         if: matrix.target