Run CI under the default service account

The vimpack-ci ServiceAccount does not exist in argocd-apps, so every step
failed at pod creation. Other non-Go repos in the estate use default.

.woodpecker/lint.yaml

@@ -9,7 +9,7 @@ steps:
       - luacheck lua plugin tests
     backend_options:
       kubernetes:
-        serviceAccountName: vimpack-ci
+        serviceAccountName: default
         resources:
           requests:
             memory: 512Mi
@@ -25,7 +25,7 @@ steps:
       - stylua --check lua plugin tests
     backend_options:
       kubernetes:
-        serviceAccountName: vimpack-ci
+        serviceAccountName: default
         resources:
           requests:
             memory: 512Mi

.woodpecker/pre-commit.yaml

@@ -10,7 +10,7 @@ steps:
       - pre-commit run --all-files --show-diff-on-failure
     backend_options:
       kubernetes:
-        serviceAccountName: vimpack-ci
+        serviceAccountName: default
         resources:
           requests:
             memory: 512Mi

.woodpecker/test.yaml

@@ -9,7 +9,7 @@ steps:
       - nvim --headless --clean -l tests/minimal.lua
     backend_options:
       kubernetes:
-        serviceAccountName: vimpack-ci
+        serviceAccountName: default
         resources:
           requests:
             memory: 512Mi