Do not fail CI when Launchable fails

It seems to randomly fail:

```
+ launchable verify
Organization: 'ruby'
Workspace: 'ruby'
Proxy: None
Platform: 'macOS-12.7.3-x86_64-i386-64bit'
Python version: '3.12.2'
Java command: 'java'
launchable version: '1.83.0'
Authentication failed. Please set the LAUNCHABLE_TOKEN. If you intend to use tokenless authentication, kindly reach out to our support team for further assistance.
```

https://github.com/ruby/ruby/actions/runs/8253299142/job/22574800261

Such failures should not impact the CI result.

.github/workflows/macos.yml

@@ -98,6 +98,7 @@ jobs:
           launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
           builddir: build
           srcdir: src
+        continue-on-error: true
 
       - name: Set extra test options
         run: echo "TESTS=$TESTS ${{ matrix.test_opts }}" >> $GITHUB_ENV

.github/workflows/ubuntu.yml

@@ -115,6 +115,7 @@ jobs:
           launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
           builddir: build
           srcdir: src
+        continue-on-error: true
 
       - name: make ${{ matrix.test_task }}
         run: >-

.github/workflows/yjit-macos.yml

@@ -122,6 +122,7 @@ jobs:
           launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
           builddir: build
           srcdir: src
+        continue-on-error: true
 
       - name: make ${{ matrix.test_task }}
         run: >-

.github/workflows/yjit-ubuntu.yml

@@ -175,6 +175,7 @@ jobs:
           launchable-token: ${{ secrets.LAUNCHABLE_TOKEN }}
           builddir: build
           srcdir: src
+        continue-on-error: true
 
       - name: make ${{ matrix.test_task }}
         run: >-