Update mdbook

Author: ehuss

.github/workflows/contrib.yml

@@ -14,7 +14,7 @@ jobs:
     - name: Install mdbook
       run: |
         mkdir mdbook
-        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.3/mdbook-v0.4.3-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
+        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.5/mdbook-v0.4.5-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
         echo `pwd`/mdbook >> $GITHUB_PATH
     - name: Deploy docs
       run: |

.github/workflows/main.yml

@@ -103,7 +103,7 @@ jobs:
     - run: cd src/doc/semver-check && cargo +stable run
     - run: |
         mkdir mdbook
-        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.3.7/mdbook-v0.3.7-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
+        curl -Lf https://github.com/rust-lang/mdBook/releases/download/v0.4.5/mdbook-v0.4.5-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
         echo `pwd`/mdbook >> $GITHUB_PATH
     - run: cargo doc --no-deps
     - run: cd src/doc && mdbook build --dest-dir ../../target/doc