ci: various fixes (#478)

- "branches" option got removed, change to "when -> branches"
- "pipeline" option got removed, change to "steps"
- install codespell in a virtual-env since alpine complains otherwise

etc/woodpecker/analysis.yml

@@ -1,6 +1,7 @@
-branches: master
+when:
+  branch: master
 
-pipeline:
+steps:
   analysis:
     image: alpine
     commands: |

etc/woodpecker/build.yml

@@ -1,7 +1,8 @@
-branches: master
+when:
+  branch: master
 
 # NOTE: "stable" tcc is too old and fails at linking. instead fetching a recent known working commit.
-pipeline:
+steps:
   build:
     image: alpine
     environment:

etc/woodpecker/spell.yml

@@ -1,10 +1,13 @@
-branches: master
+when:
+  branch: master
 
-# NOTE: codespell not available on stable alpine, use edge
-pipeline:
+# NOTE: codespell not available on stable alpine, grab it from pip
+steps:
   spell-check:
     image: alpine:edge
     commands: |
       apk add --no-cache python3 py3-pip git
+      python3 -m venv ~/py3-venv
+      . ~/py3-venv/bin/activate
       pip install codespell
       git ls-files | sed '/\.png$/d' | xargs codespell