ci: remove cross-platform-tests and semantic PR/branch checks (#712)

These checks have been failing on nearly every recent PR. The
cross-platform tests are known broken, and the semantic PR title /
branch name checks are no longer enforced.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jamesnrokt

.github/workflows/cross-platform-tests.yml

@@ -27,12 +27,6 @@ jobs:
   pr-check-hadcoded-secrets:
     name: "Check PR for hardcoded secrets"
     uses: mParticle/mparticle-workflows/.github/workflows/security-hardcoded-secrets.yml@main
-  pr-branch-check-name:
-    name: "Check PR for semantic branch name"
-    uses: mParticle/mparticle-workflows/.github/workflows/pr-branch-check-name.yml@main
-  pr-title-check:
-    name: "Check PR for semantic title"
-    uses: mParticle/mparticle-workflows/.github/workflows/pr-title-check.yml@main
 
   instrumented-tests:
     name: "Instrumented Tests"