*: convert to single-module architecture

The Go project recommends single-module repositories over multi-module
wherever possible [1]; multi-module setups seem to be most useful when they
represent separately-versioned and released projects living within the same
repository (further analysis in [2]). Additionally, there is currently no
convenient way to test all modules in a 'go.work' file (see [3]).

Due to the factors listed, convert repository from multi- to single-module.

[1] https://github.com/golang/go/wiki/Modules#should-i-have-multiple-modules-in-a-single-repository
[2] https://medium.com/compass-true-north/catching-up-with-the-world-go-modules-in-a-monorepo-c3d1393d6024
[3] golang/go#50745

Signed-off-by: Victoria Dye <vdye@github.com>

Author: vdye

.github/workflows/main.yml

@@ -21,13 +21,11 @@ jobs:
       - name: Build
         run: |
           cd $GITHUB_WORKSPACE/src/git-bundle-server
-          go build ./cmd/git-bundle-server
-          go build ./cmd/git-bundle-web-server
+          go build -v ./...
 
       - name: Check style
         run: |
           cd $GITHUB_WORKSPACE/src/git-bundle-server
-          go vet ./cmd/git-bundle-server
-          go vet ./cmd/git-bundle-web-server
+          go vet ./...
 
       # TODO: add automated tests.

cmd/git-bundle-server/go.mod

@@ -1,8 +1,3 @@
 module github.com/github/git-bundle-server
 
 go 1.19
-
-require (
-	golang.org/x/lint v0.0.0-20210508222113-6edffad5e616 // indirect
-	golang.org/x/tools v0.1.12 // indirect
-)