go.mod: downgrade deps for litd release

lnd v0.19.3-beta
tapd v0.6.1
go 1.23.12 (except in tools/ where golangci-lint needs Go 1.24)

Remove docs generators as cli-docs depends on Go 1.24.

.github/workflows/main.yml

@@ -20,7 +20,7 @@ env:
 
   # If you change this value, please change it in the following files as well:
   # /Dockerfile
-  GO_VERSION: 1.24.6
+  GO_VERSION: 1.23.12
 
 jobs:
   ########################
@@ -103,26 +103,6 @@ jobs:
       - name: lint
         run: make lint
 
-  ########################
-  # Verify documentation
-  ########################
-  docs-check:
-    name: verify that auto-generated documentation is up-to-date
-    runs-on: ubuntu-latest
-    steps:
-      - name: git checkout
-        uses: actions/checkout@v2
-        with:
-          fetch-depth: 0
-
-      - name: setup go ${{ env.GO_VERSION }}
-        uses: actions/setup-go@v5
-        with:
-          go-version: '~${{ env.GO_VERSION }}'
-
-      - name: check
-        run: make docs-check
-
   ########################
   # run unit tests
   ########################