chore: fix multiline string variable in workflow [skip ci]

.github/workflows/upgrade-dependencies.yaml

@@ -18,11 +18,15 @@ jobs:
       - name: Get the output from yarn outdated and save it in a variable to reference in the PR body
         id: yarn
         # See: https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#multiline-strings
+        # See also https://github.com/github/docs/issues/21529 for more info on why this is not quite so simple
         run: |
+          yarn outdated > outdated.txt
+          YARN_OUTDATED=$(cat outdated.txt)
           EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
           echo "outdated<<$EOF" >> "$GITHUB_OUTPUT"
-          yarn outdated >> "$GITHUB_OUTPUT"
+          echo "$YARN_OUTDATED" >> "$GITHUB_OUTPUT"
           echo "$EOF" >> "$GITHUB_OUTPUT"
+          rm outdated.txt
       - name: Do the upgrade
         run: yarn upgrade
       - name: Create Pull Request

outdated.txt

@@ -0,0 +1,19 @@
+yarn outdated v1.22.22
+info Color legend : 
+ "<red>"    : Major Update backward-incompatible updates 
+ "<yellow>" : Minor Update backward-compatible features 
+ "<green>"  : Patch Update backward-compatible bug fixes
+Package                          Current  Wanted   Latest  Package Type    URL                                                                               
+@cdktf/provider-github           13.2.0   13.2.0   14.2.2  dependencies    https://github.com/cdktf/cdktf-provider-github#readme                             
+@types/node                      18.19.29 18.19.39 20.14.9 devDependencies https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/node         
+@typescript-eslint/eslint-plugin 6.21.0   6.21.0   7.15.0  devDependencies https://typescript-eslint.io/packages/eslint-plugin                               
+@typescript-eslint/parser        6.21.0   6.21.0   7.15.0  devDependencies https://typescript-eslint.io/packages/parser                                      
+cdktf                            0.20.6   0.20.8   0.20.8  dependencies    https://github.com/hashicorp/terraform-cdk                                        
+cdktf-cli                        0.20.6   0.20.8   0.20.8  dependencies    https://github.com/hashicorp/terraform-cdk#readme                                 
+change-case                      4.1.2    4.1.2    5.4.4   dependencies    https://github.com/blakeembrey/change-case/tree/master/packages/change-case#readme
+eslint                           8.57.0   8.57.0   9.6.0   devDependencies https://eslint.org                                                                
+lint-staged                      15.2.2   15.2.7   15.2.7  devDependencies https://github.com/okonet/lint-staged#readme                                      
+prettier                         3.2.5    3.3.2    3.3.2   devDependencies https://prettier.io                                                               
+tsx                              4.7.2    4.16.0   4.16.0  devDependencies https://tsx.is                                                                    
+typescript                       5.3.3    5.3.3    5.5.3   devDependencies https://www.typescriptlang.org/                                                   
+Done in 2.96s.