fixup: remove caddy submodule

Author: not-matthias

.gitmodules

@@ -7,9 +7,6 @@
 [submodule "go-runner/testdata/projects/golang-benchmarks"]
 	path = go-runner/testdata/projects/golang-benchmarks
 	url = https://github.com/SimonWaldherr/golang-benchmarks
-[submodule "go-runner/testdata/projects/caddy"]
-	path = go-runner/testdata/projects/caddy
-	url = https://github.com/caddyserver/caddy
 [submodule "go-runner/testdata/projects/fuego"]
 	path = go-runner/testdata/projects/fuego
 	url = https://github.com/go-fuego/fuego