Cleanup build

No functional changes here, just a few housekeeping things:

1) Renamed it to "build.yml" and "Buildroot" since it's responsibilities have now expanded.

2) Got rid of all the caching stuff since we're not using it any more.

3) Updated the upload-artifact action to v3 to resolve the warnings Github was logging about v2 using a deprecated node.js version

.github/workflows/build.yml

@@ -0,0 +1,103 @@
+name: Buildroot
+on:
+  push:
+  pull_request:
+  workflow_call:
+    inputs:
+      submodule:
+        description: The directory of the submodule, if this workflow is being called on a submodule
+        required: true
+        type: string
+
+jobs:   
+  build-image-uclibc:
+    runs-on: ubuntu-22.04
+    env:
+      FORCE_UNSAFE_CONFIGURE: 1
+    steps:
+    - uses: actions/checkout@v3
+    - if: inputs.submodule
+      run: git submodule update --init --depth 1 -- ${{ inputs.submodule }}
+        
+    - name: build
+      run: |
+        cd ${{ inputs.submodule || '.' }}
+        #apt update && apt install -y wget unzip build-essential git bc swig libncurses-dev libpython3-dev libssl-dev cpio rsync subversion
+        make miyoo_uclibc_defconfig
+        make sdk
+ 
+    - name: generate-graphs
+      run: |
+        cd ${{ inputs.submodule || '.' }}
+        sudo apt update && sudo apt install -y python3-matplotlib python3-numpy
+        make graph-build
+      
+    - uses: actions/upload-artifact@v3
+      with:
+        name: build image (uClibc)
+        path: ${{ inputs.submodule || '.' }}/output/images/miyoo-cfw-*.img
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn`
+        
+    - uses: actions/upload-artifact@v3
+      with:
+        name: SDK (uClibc)
+        path: ${{ inputs.submodule || '.' }}/output/images/arm-miyoo-linux-uclibcgnueabi_sdk-buildroot.tar.gz
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn`    
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: build-graphs (uClibc)
+        path: ${{ inputs.submodule || '.' }}/output/graphs/
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn` 
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: rootfs (uClibc)
+        path: ${{ inputs.submodule || '.' }}/output/images/rootfs.ext4
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn`   
+
+  build-image-musl:
+    runs-on: ubuntu-22.04
+    env:
+      FORCE_UNSAFE_CONFIGURE: 1
+    steps:
+    - uses: actions/checkout@v3
+    - if: inputs.submodule
+      run: git submodule update --init --depth 1 -- ${{ inputs.submodule }}
+    
+    - name: build
+      run: |
+        cd ${{ inputs.submodule || '.' }}
+        #apt update && apt install -y wget unzip build-essential git bc swig libncurses-dev libpython3-dev libssl-dev cpio rsync subversion
+        make miyoo_musl_defconfig
+        make sdk
+
+    - name: generate-graphs
+      run: |
+        cd ${{ inputs.submodule || '.' }}
+        sudo apt update && sudo apt install -y python3-matplotlib python3-numpy
+        make graph-build
+      
+    - uses: actions/upload-artifact@v3
+      with:
+        name: build image (musl)
+        path: ${{ inputs.submodule || '.' }}/output/images/miyoo-cfw-*.img
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn`
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: SDK (musl)
+        path: ${{ inputs.submodule || '.' }}/output/images/arm-miyoo-linux-musleabi_sdk-buildroot.tar.gz
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn` 
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: build-graphs (musl)
+        path: ${{ inputs.submodule || '.' }}/output/graphs/
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn` 
+
+    - uses: actions/upload-artifact@v3
+      with:
+        name: rootfs (musl)
+        path: ${{ inputs.submodule || '.' }}/output/images/rootfs.ext4
+        if-no-files-found: error # 'error', 'warn', 'ignore'; defaults to `warn`