Generalize branch references to HEAD

.github/ISSUE_TEMPLATE/tracking_issue.md

@@ -50,7 +50,7 @@ for larger features an implementation could be broken up into multiple PRs.
 [stabilization-guide]: https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#stabilization-pr
 [doc-guide]: https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#documentation-prs
 [nightly-style-procedure]: https://github.com/rust-lang/style-team/blob/main/nightly-style-procedure.md 
-[Style Guide]: https://github.com/rust-lang/rust/tree/master/src/doc/style-guide
+[Style Guide]: https://github.com/rust-lang/rust/tree/HEAD/src/doc/style-guide
 
 ### Unresolved Questions
 <!--

.github/workflows/ci.yml

@@ -323,7 +323,7 @@ jobs:
       # If a some dependent job has failed, this exits with 1.
       - name: calculate the correct exit status
         run: jq --exit-status 'all(.result == "success" or .result == "skipped")' <<< '${{ toJson(needs) }}'
-      # Publish the toolstate if an auto build succeeds (just before push to master)
+      # Publish the toolstate if an auto build succeeds (just before push to the default branch)
       - name: publish toolstate
         run: src/ci/publish_toolstate.sh
         shell: bash

.github/workflows/post-merge.yml

@@ -1,4 +1,4 @@
-# Workflow that runs after a merge to master, analyses changes in test executions
+# Workflow that runs after a merge to the default branch, analyses changes in test executions
 # and posts the result to the merged PR.
 
 name: Post merge analysis