Pin GitHub Actions (#230)

## Summary
- Pin all GitHub Actions references to commit SHAs

This pull request was AI-assisted by Isaac.

Author: pietern

.github/workflows/release-pr.yml

@@ -15,7 +15,7 @@ jobs:
       labels: linux-ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           fetch-depth: 0
           fetch-tags: true

.github/workflows/tag.yml

@@ -16,7 +16,7 @@ jobs:
       labels: linux-ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           fetch-depth: 0
           fetch-tags: true

.github/workflows/test.yml

@@ -28,7 +28,7 @@ jobs:
           - windows-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           path: ./setup-cli
 
@@ -55,7 +55,7 @@ jobs:
           - windows-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           path: ./setup-cli
 
@@ -84,7 +84,7 @@ jobs:
           - windows-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           path: ./setup-cli
 
@@ -120,7 +120,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           path: ./setup-cli
 
@@ -162,7 +162,7 @@ jobs:
           - windows-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           path: ./setup-cli
 
@@ -194,7 +194,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           path: ./setup-cli
 
@@ -226,7 +226,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
         with:
           path: ./setup-cli