chore: Finish bumping go's version to 1.23. (#99)

This was overlooked in 71c288e (#39).

This didn't cause any problems that I noticed, but I thought it was odd
that the github actions weren't using the version advertised in the
readme.

Author: JeffFaer

.github/workflows/go.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: "1.21"
+          go-version: "1.23"
 
       - name: Build
         run: go build -v .

.github/workflows/publish-release-artifacts.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v3
         with:
-          go-version: "1.21"
+          go-version: "1.23"
 
       - name: Build
         run: go build -v .