Rename ios_packaging.requirements.txt to ios_packaging/requirements.txt (#21936)

### Description
Rename ios_packaging.requirements.txt to ios_packaging/requirements.txt



### Motivation and Context
By doing this, the package within os_packaging/requirements.txt can be
scanned by CG task

tools/ci_build/github/azure-pipelines/post-merge-jobs.yml

@@ -439,7 +439,7 @@ stages:
         xcodeVersion: 14.2
 
     - script: |
-        pip install -r tools/ci_build/github/apple/ios_packaging.requirements.txt
+        pip install -r tools/ci_build/github/apple/ios_packaging/requirements.txt
       displayName: "Install Python requirements"
 
     - script: |
@@ -477,7 +477,7 @@ stages:
         xcodeVersion: 14.2
 
     - script: |
-        pip install -r tools/ci_build/github/apple/ios_packaging.requirements.txt
+        pip install -r tools/ci_build/github/apple/ios_packaging/requirements.txt
       displayName: "Install Python requirements"
 
     - script: |

tools/ci_build/github/azure-pipelines/templates/react-native-ci.yml

@@ -61,7 +61,7 @@ stages:
         architecture: "x64"
 
     - script: |
-        pip install -r tools/ci_build/github/apple/ios_packaging.requirements.txt
+        pip install -r tools/ci_build/github/apple/ios_packaging/requirements.txt
       displayName: "Install Python requirements"
 
     - template: mac-build-step-with-cache.yml

tools/ci_build/github/azure-pipelines/templates/stages/mac-ios-packaging-build-stage.yml

@@ -68,7 +68,7 @@ stages:
     - template: ../install-appcenter.yml
 
     - script: |
-        pip install -r tools/ci_build/github/apple/ios_packaging.requirements.txt
+        pip install -r tools/ci_build/github/apple/ios_packaging/requirements.txt
       displayName: "Install Python requirements"
 
     # create and test mobile pods