Fix warnings when using typst 0.12.0 (#71)

* fixes for warnings with typst 0.12.0
* update tests for typst 0.12.0
* update github test workflow for typst 0.12
* chore: apply typst updates to test code
* chore: update compiler version in typst.toml
* chore: use the correct preview version in coverletter2
* chore: improve comments in coverletter template
* chore: update test references
* fix: issues with coverletter for typst `0.12.0`
* update test references with typst-test update

---------

Co-authored-by: Paul Tsouchlos <developer.paul.123@gmail.com>

template/coverletter.typ

@@ -19,7 +19,9 @@
   profile-picture: image("./profile.png"),
   language: "en",
   font: "Times New Roman",
-  // show-footer: false, // Uncomment to hide footer
+  // Remove the following line to show the footer
+  // Or set the value to `true`
+  show-footer: false,
 )
 
 #hiring-entity-info(entity-info: (

template/coverletter2.typ

@@ -1,4 +1,4 @@
-#import "@preview/modern-cv:0.5.0": *
+#import "@preview/modern-cv:0.7.0": *
 
 #show: coverletter.with(
   author: (