build: change the fallback version suffix to `+git.{sha}`

Seems to be more commonly used than the current `-commit-{sha}`.
Also cleanup/simplify the version handling code and fix the list
of dependencies in the CI scripts.

Change-Id: I4d8826d1012d128883773b7517c44a6abf51fa06
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1ff7602..74f5cd3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,9 +2,13 @@
 on:
   push:
     paths-ignore:
+      - 'Dockerfile'
+      - '.dockerignore'
       - 'docs/**'
-      - '*.md'
+      - '.editorconfig'
+      - '.gitignore'
       - '.mailmap'
+      - '*.md'
   workflow_dispatch:
 
 permissions: {}